plzzz.... EXPLAIN MITOSIS AND MEIOSIS

Please follow the link-

https://www.meritnation.com/ask-answer/question/what-are-the-differences-between-mitotic-and-meotic-cell-div/how-do-organisms-reproduce/635784

View Full Answer

Mitosis and MeiosisWhat is Mitosis?

Mitosis produces two daughter cells that are identical to the parent cell. If the parent cell is haploid (N), then the daughter cells will be haploid. If the parent cell is diploid, the daughter cells will also be diploid.

N → N

2N → 2N

This type of cell division allows multicellular organisms to grow and repair damaged tissue.

Click here to go to the chapter on Mitosis.

Summary of the Phases of Mitosis

The drawings below show chromosome movement and alignment in a cell from a species of animal that has a diploid number of 8. As you view the drawings, keep in mind that humans have a diploid number of 46.

Interphase (G₁and G₂)Chromosomes are not easily visible because they are uncoiled.

ProphaseThe chromosomes begin to coil.The spindle apparatus begins to form as centrosomes move apart.

PrometaphaseThe nuclear membrane disintegrates.Kinetochores form on the chromosomes.Kinetochore microtubules attach to the chromosomes.

MetaphaseThe chromosomes become aligned on a plane.

AnaphaseThe chromatids separate (The number of chromosomes doubles).

TelophaseThe nuclear membrane reappears.The chromosomes uncoil.The spindle apparatus breaks down.The cell divides into two.

G₁InterphaseThe chromosomes have one chromatid.

G₂InterphaseThe chromosomes are replicated. Each one has two sister chromatids.What is Meiosis?

Meiosis produces daughter cells that have one half the number of chromosomes as the parent cell.

2N → N

Meiosis enables organisms to reproducesexually. Gametes (sperm and eggs) are haploid.

Meiosis involves two divisions producing a total of four daughter cells.

Summary of thePhases of Meiosis

A cell undergoing meiosis will divide two times; the first division is meiosis 1 and the second is meiosis 2. The phases have the same names as those of mitosis. A number indicates the division number (1st or 2nd):

meiosis 1: prophase 1, metaphase 1, anaphase 1, and telophase 1

meiosis 2: prophase 2, metaphase 2, anaphase 2, and telophase 2

In the first meiotic division, the number of cells is doubled but the number of chromosomes is not. This results in 1/2 as many chromosomes per cell.

The second meiotic division is like mitosis; the number of chromosomes does not get reduced.

Prophase I

Homologous chromosomes become paired.

Crossing-over occurs between homologous chromosomes.

Crossing over

Metaphase I

Homologous pairs become aligned in the center of the cell.

The random alignment pattern is called independent assortment. For example, a cell with 2N = 6 chromosomes could have any of the alignment patterns shown at the left..