How many types of platids are there ? write function of each plastids.

Different types of plastids are as follows:

  • Chloroplasts: They have chlorophyll as a pigment. Their function is to carry out photosynthesis. They are green in color because of presence of chlorophyll.
  • Chromoplasts: They have different kinds of pigments which are responsible for color so they can be of any color like red, yellow orange depending upon the pigment they have. They are usually present in petals of flower in order to make flower attractive to pollinators.
  • Amyloplasts: They are starch storing plastids.
  • Leucoplasts: they store lipids, proteins and starch. They are colorless in appearance.

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Plastids

In most plant cells structures called plastids are found. They are found in the cytoplasmic matrix of plant cells only. These structures are generally spherical or ovoid in shape and they are clearly visible in living cells. We will discuss 3 types of plastids found in plant cells:

Chromoplasts

Chromoplasts are red, yellow or orange in colour and are found in petals of flowers and in fruit. Their colour is due to two pigments, carotene and xanthophyll.

    Functions

  • the primary function in the cells of flowers is to attract agents of pollination,
  • and in fruit to attract agents of dispersal.
Leucoplasts

Leucoplasts are colourless plastids and occur in plant cells not exposed to light, such as roots and seeds. They are colourless due the absent of pigments.

    Functions

  • leucoplasts are the centers of starch grain formation;
  • they are also involved in the synthesis of oils and proteins.
Chloroplasts

Chloroplasts are probably the most important among the plastids since they are directly involved in photosynthesis. They are usually situated near the surface of the cell and occur in those parts that receive sufficient light, e.g. the palisade cells of leaves. The green colour of chloroplasts is caused by the green pigment chlorophyll.

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Plastids

In most plant cells structures called plastids are found. They are found in the cytoplasmic matrix of plant cells only. These structures are generally spherical or ovoid in shape and they are clearly visible in living cells. We will discuss 3 types of plastids found in plant cells:

Chromoplasts

Chromoplasts are red, yellow or orange in colour and are found in petals of flowers and in fruit. Their colour is due to two pigments, carotene and xanthophyll.

    Functions

  • the primary function in the cells of flowers is to attract agents of pollination,
  • and in fruit to attract agents of dispersal.
Leucoplasts

Leucoplasts are colourless plastids and occur in plant cells not exposed to light, such as roots and seeds. They are colourless due the absent of pigments.

    Functions

  • leucoplasts are the centers of starch grain formation;
  • they are also involved in the synthesis of oils and proteins.
Chloroplasts

Chloroplasts are probably the most important among the plastids since they are directly involved in photosynthesis. They are usually situated near the surface of the cell and occur in those parts that receive sufficient light, e.g. the palisade cells of leaves. The green colour of chloroplasts is caused by the green pigment chlorophyll.

Structure

Chloroplasts are usually disc-shaped and surrounded by a double membrane. Inside the inner membrane there is a watery protein-rich ground substance orstroma in which is embedded a continuous membrane system, the granal network. This network forms a three- dimensional arrangement of membrane-bound vesicles called thylakoids. The thylakoids usually lie in stacks called grana and contain the photosynthetic pigments - green chlorophyll a and b and the yellow to red carotenoids. The grana are interconnected by tubular membranes called the intergranal frets or lamellae.

Functions

  • chloroplasts are the sites for photosynthesis;
  • they contain enzymes and co-enzymes necessary for the process of photosynthesis.

A typical chloroplast

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These are Leucoplasts: storage plastids (named after what they store) 
Amyloplast which stores starch 
Elaioplast which stores oils and lipids 
Proteinoplast...self explanatory. 

These have other functions that may or may not include pigments to effect their colors. 
Chromoplast which is rich in chlorophyll and undergoes photosynthesis 
Etioplasts which are chloroplast that have not been exposed to light. Very commonly found in angiosperms grown in the dark 
Proplastid which is a very young plastid found in meristomatic cells (growth cells)

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