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Description of a typical plant cell.
Asked by Bharaniben(student) , on 11/7/13


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Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioleslysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 

Posted by Himanshi Sharma(student)on 15/5/13

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Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioleslysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 

Posted by Himanshi Sharma(student)on 15/5/13

I hope it will help............... uuuuuu

Posted by Himanshi Sharma(student)on 15/5/13

Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on  plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on  structure and functions of cytoplasm .

List of Plant Cell Organelles 
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for  photosynthesis . Following is a list of organelles found in plant cell:

Nucleus 
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on  cell nucleus .

Plastids 
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the  importance of photosynthesis .

Ribosomes 
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each  ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria 
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body 
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum 
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles 
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes 
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on  plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

Posted by Vivek Tripathi(student)on 16/5/13

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in  animal cells . Link to pages describing these.

 Plant cells differ from animal cells in lacking:

and having:

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 µm in diameter and 2-4 µm thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large  central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is  hypertonic  to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly.

Posted by Rishabh Tripath...(student)on 16/5/13

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Plant Cell
Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

Posted by Himanshi Sharma(student) 15 hours, 39 minutes ago

 
 
 
    0  0

 

I hope it will help............... uuuuuu

 

Posted by Himanshi Sharma(student) 15 hours, 30 minutes ago

 
 
 
    0  0

 

Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
    0  0

 

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

Posted by Karthikeya Elap...(student)on 16/5/13

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Select Subject Math Science Hindi English Social Science GK Summer Pack Vedic Math PSA Tests Select Chapter Matter in Our Surroundings Is Matter Around Us Pure Atoms and Molecules Structure of the Atom The Fundamental Unit of Life Tissues Diversity in Living Organisms Motion Force and Laws of Motion Gravitation Work and Energy Sound Why Do We Fall Ill Natural Resources Improvement in Food Resources Apply

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Plant Cell
Plant Cell
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CBSE Class 6, 7, 8, 9, 10 www.SmartLearning.in NCERT Solutions of Maths, Science Social Science & English. Join Now.

Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

Posted by Himanshi Sharma(student) 15 hours, 39 minutes ago

 
 
 
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I hope it will help............... uuuuuu

 

Posted by Himanshi Sharma(student) 15 hours, 30 minutes ago

 
 
 
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Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
    0  0

 

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

Posted by Karthikeya Elap...(student)on 16/5/13

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Plant Cell
Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

Posted by Himanshi Sharma(student) 15 hours, 39 minutes ago

 
 
 
    0  0

 

I hope it will help............... uuuuuu

 

Posted by Himanshi Sharma(student) 15 hours, 30 minutes ago

 
 
 
    0  0

 

Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
    0  0

 

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

Posted by Karthikeya Elap...(student)on 16/5/13

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Select Subject Math Science Hindi English Social Science GK Summer Pack Vedic Math PSA Tests Select Chapter Matter in Our Surroundings Is Matter Around Us Pure Atoms and Molecules Structure of the Atom The Fundamental Unit of Life Tissues Diversity in Living Organisms Motion Force and Laws of Motion Gravitation Work and Energy Sound Why Do We Fall Ill Natural Resources Improvement in Food Resources Apply

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Plant Cell
Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

Posted by Himanshi Sharma(student) 15 hours, 39 minutes ago

 
 
 
    0  0

 

I hope it will help............... uuuuuu

 

Posted by Himanshi Sharma(student) 15 hours, 30 minutes ago

 
 
 
    0  0

 

Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
    0  0

 

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

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Plant Cell
Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

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Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
    0  0

 

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

Posted by Karthikeya Elap...(student)on 16/5/13

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Select Subject Math Science Hindi English Social Science GK Summer Pack Vedic Math PSA Tests Select Chapter Matter in Our Surroundings Is Matter Around Us Pure Atoms and Molecules Structure of the Atom The Fundamental Unit of Life Tissues Diversity in Living Organisms Motion Force and Laws of Motion Gravitation Work and Energy Sound Why Do We Fall Ill Natural Resources Improvement in Food Resources Apply

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Plant Cell
Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

Posted by Himanshi Sharma(student) 15 hours, 39 minutes ago

 
 
 
    0  0

 

I hope it will help............... uuuuuu

 

Posted by Himanshi Sharma(student) 15 hours, 30 minutes ago

 
 
 
    0  0

 

Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
    0  0

 

The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

Posted by Karthikeya Elap...(student)on 16/5/13

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Select Subject Math Science Hindi English Social Science GK Summer Pack Vedic Math PSA Tests Select Chapter Matter in Our Surroundings Is Matter Around Us Pure Atoms and Molecules Structure of the Atom The Fundamental Unit of Life Tissues Diversity in Living Organisms Motion Force and Laws of Motion Gravitation Work and Energy Sound Why Do We Fall Ill Natural Resources Improvement in Food Resources Apply

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Asked by Alisha chunduri 0 Seconds ago Subject :Science
 
 
 
 

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Plant Cell
Plant Cell
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Plant Cell

Image Credit: Mariana Ruiz/Modified by Dhatfield

Plant Cell

Plant cells are eukaryotic cells, or cells with a membrane-bound nucleus. Unlike prokaryotic cells, the DNA in a plant cell is housed within the nucleus. In addition to having a nucleus, plant cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for a plant cell.

Plant cells are similar to animal cells in that they are both eukaryotic cells and have similar organelles. Plant cells are generally larger than animal cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, and cilia and flagella that are not typically found in plant cells.

Plant Cell: Structures and Organelles

The following are examples of structures and organelles that can be found in typical plant cells:
  • Cell (Plasma) Membrane - a thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.

  • Cell Wall - outer covering of the cell that protects the plant cell and gives it shape.

  • Chloroplasts - the sites of photosynthesis in a plant cell. They contain chlorophyll, a green pigment that absorbs energy from sunlight.

  • Cytoplasm - gel-like substance within the cell membrane containing water, enzymes, salts, organelles, and various organic molecules.

  • Cytoskeleton - a network of fibers throughout the cytoplasm that helps the cell maintain its shape and gives support to the cell.

  • Endoplasmic Reticulum (ER) - extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).

  • Golgi Complex - responsible for manufacturing, storing and shipping certain cellular products.

  • Microtubules - hollow rods that function primarily to help support and shape the cell.

  • Mitochondria - this organelle generates energy for the cell.

  • Nucleus - membrane bound structure that contains the cell 's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.

    • Nucleopore - tiny hole within the nuclear membrane that allows nucleic acids and proteinsto move into and out of the nucleus.
  • Peroxisomes - tiny structures bound by a single membrane that contain enzymes that produce hydrogen peroxide as a by-product. These structures are involved in plant processes such as photorespiration.

  • Plasmodesmata - pores or channels between plant cell walls that allow molecules and communication signals to pass between individual plant cells.

  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

  • Vacuole - structure in a plant cell that provides support and participates in a variety of cellular functions including storage, detoxification, protection, and growth. When a plant cell matures, it typically contains one large liquid-filled vacuole.

Plant Cell Types

As a plant matures, its cells become specialized in order to perform certain functions necessary for survival. Some plant cells synthesize and store organic products, while others help to transport nutrients throughout the plant. Some examples of specialized plant cell types include:
  • Parenchyma Cells - although not highly specialized, these cells synthesize and store organic products in the plant.

  • Collenchyma Cells - help to support plants while not restraining growth due to their lack of secondary walls and the absence of a hardening agent in their primary walls.

  • Sclerenchyma Cells - provide a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid.
Plant cells are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type. Above and beyond tissues, plants also have a higher level of structure called plant tissue systems. There are three types of tissue systems: dermal tissue, vascular tissue, and ground tissue systems.
 
Plant Cells
  • Types of Plant Cells
  • Plant Tissue Systems
  • Cell Facts
Plant Cell Division
  • Mitosis
  • Mitosis Image Gallery
  • Mitosis Quiz
Plants
  • Angiosperms
  • Unusual Plants
  • Carnivorous Plants

 

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I hope it will help............... uuuuuu

 

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Plants are highly evolved eukaryotic organisms that comprise membrane bound cell organelles. Even though plants and animals belong to eukaryotic groups, they differ in certain characteristic features. For example, a plant cell possesses a well-developed cell wall and large vacuoles, while an animal cell lacks such structural parts. In addition to these, a plant cell lacks centrioles and intermediate filaments, which are present in an animal cell. Read more on plant cell model .

A typical plant cell is made up of cytoplasm and organelles. Scientific studies have been done regarding plant cell organelles and their functions. Each of the organelles of a plant cell has specific functions, without which the cell cannot operate properly. Read more on structure and functions of cytoplasm .

List of Plant Cell Organelles
When it comes to plant cell organelles, they are more or less similar to animal cells, except that the latter lacks chloroplast organelles, that are responsible for photosynthesis . Following is a list of organelles found in plant cell:

Nucleus
Nucleus (plural nuclei) is a highly specialized cell organelle, which stores the genetic component (chromosomes) of the particular cell. It serves as the main administrative center of the cell, by coordinating the metabolic processes like cell growth, cell division and protein synthesis. Read more on cell nucleus .

Plastids
Plastids are collective terms for organelles that carry pigments. In a plant cell, chloroplasts are the most prominent forms of plastids, that contain the green chlorophyll pigment. Because of these chloroplast plastids, a plant cell has the ability to undergo photosynthesis in the presence of sunlight and synthesize its own food. Read more on the importance of photosynthesis .

Ribosomes
Ribosomes are plant cell organelles that comprise proteins (40 percent) and ribonucleic acid or RNA (60 percent). They are important organelles responsible for the synthesis of proteins. Each ribosome consists of two parts, a larger subunit and a smaller subunit.

Mitochondria
Mitochondria (singular mitochondrion) are spherical to rod-shaped organelles present in the cytoplasm of the plant cell. They break down the complex carbohydrates and sugars into usable forms, for the plant. As mitochondria indirectly supply energy for the plant cell, they are also known as the powerhouse of the cell.

Golgi Body
Golgi body is also referred to as golgi complex or golgi apparatus. It plays a major role in transporting chemical substances in and out of the cell. After the endoplasmic reticulum synthesizes lipids and proteins, golgi body alters and prepares them for exporting outside the cell.

Endoplasmic Reticulum
Endoplasmic reticulum (ER) is the connecting link between the nucleus and cytoplasm of the plant cell. Basically, it is a network of interconnected and convoluted sacs that are located in the cytoplasm. Based on the presence or absence of ribosomes, ER can be of smooth or rough types. The former type lacks ribosomes, while the latter is covered with ribosomes. Overall, endoplasmic reticulum serves as a manufacturing, storing and transporting structure for glycogen, proteins, steroids and other compounds.

Vacuoles
Vacuoles are the storage organelles that help in regulating turgor pressure of the plant cell. In a plant cell, there can be more than one vacuole. However, the centrally located vacuole is larger than others, which stores all sorts of chemical compounds. Vacuoles also assist in intracellular digestion of complex molecules and excretion of waste products.

Peroxisomes
Peroxisomes are cytoplasmic organelles of the plant cell, which contains certain oxidative enzymes. These enzymes are used for the metabolic breakdown of fatty acids into simple sugar forms. Another important function of peroxisomes is to help chloroplasts in undergoing photorespiration process. Read more on plant cell structure and parts .

Well! This was a brief information regarding plant cell organelles, their structure and specific functions. As we have seen, coordination of the functions of plant cell organelles is crucial for carrying out the physiological and biochemical functionalities of the plant

 

Posted by Vivek Tripathi(student) 5 hours, 51 minutes ago

 
 
 
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The Plant Cell

Plant cells are eukaryotic and have many of the structures found in animal cells . Link to pages describing these.

  • Plasma membrane
  • Nucleus and nucleolus
  • Mitochondria
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisomes (the crystal in the electron micrograph is enclosed within a peroxisome)
  • Microtubules

  Plant cells differ from animal cells in lacking:

  • centrioles
  • intermediate filaments

and having:

  • plastids
  • a cell wall
  • large vacuoles

The electron micrograph shows cells from a sunflower leaf. It was supplied through the courtesy of H. J. Arnott and Kenneth M. Smith.

Plastids

Chloroplasts are the most familiar plastids. They are usually disk-shaped and about 5-8 �m in diameter and 2-4 �m thick. A typical plant cell has 20-40 of them.

Link to page on chloroplast structure.

Chloroplasts are green because they contain chlorophylls — the pigments that harvest the light used in photosynthesis.

Link to Chlorophyll
Links to Photosynthesis

Chloroplasts are probably the descendants of cyanobacteria that took up residence in the ancestor of the plants.

Link to discussion of the endosymbiotic origin of chloroplasts.

Plant cells that are not engaged in photosynthesis also have plastids that serve other functions, such as

  • storing starch (when they are called leucoplasts) [View]
  • storing the carotenoids that give flowers and fruits their color (when they are called chromoplasts).

The Cell Wall

The rigid cell wall of plants is made of fibrils of cellulose embedded in a matrix of several other kinds of polymers such as pectin and lignin.

Link to a picture showing how fibrils of cellulose are deposited in the cell wall.

The linear nature of cellulose molecules and the many opportunities for side-to-side intermolecular hydrogen bonding provide just what one would want to build long, stiff fibrils.

Primary cell walls

The cell walls of parenchyma and meristems are uniform in thickness and are primary cell walls.

Although each cell appears encased within a box, in fact primary cell walls are perforated permitting plasmodesmata to connect adjacent cells.

Secondary cell walls

The cells of

  • sclerenchyma
  • collenchyma
  • xylem

have secondary deposits of lignified cellulose which provide mechanical strength to the tissue.

Vacuoles

Vacuoles are enclosed by a single membrane. Young plant cells often contain many small vacuoles, but as the cells mature, these unite to form a large central vacuole . Vacuoles serve several functions, such as

  • storing foods (e.g., proteins in seeds)
  • storing wastes
  • storing malic acid in CAM plants
  • storing various ions (e.g., calcium, sodium, iron) which, among other functions, helps to
  • maintain turgor in the cell.

Plant cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the build-up of turgor within the cell. Loss of turgor causes wilting.

Plasmolysis

When a freshwater (or terrestrial) plant is placed in sea water, its cells quickly lose turgor and the plant wilts.

This is because sea water is hypertonic to the cytoplasm. As water diffuses from the cytoplasm into the sea water, the cells shrink — drawing their plasma membrane away from the cell wall.

The photomicrograph shows plasmolyzed cells in the freshwater plant Elodea which has been placed in sea water. Note how the cell walls now show clearly

Posted by Karthikeya Elap...(student)on 16/5/13

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