Question

define following in short:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
5. Karyokinesis
6. Cytokinesis

I'll spam anything unrelated to this stuff.

15 points for the answer XD



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Answer 1

Answer:

A pair of each type of chromosome is present

in 2n condition whereas single chromosome of each

type is present in n condition

Somatic cells and stem cells divide by mitosis.

Mitosis is completed through two main steps. Those

two steps are karyokinesis (nuclear division) and

cytokinesis (cytoplasmic division). Karyokinesis is

completed through four steps.

A. Prophase : In prophase, condensation of

basically thin thread-like chromosomes starts. Due

to this, they become short and thick and they start

to appear along with their pairs of sister chromatids.

Centrioles duplicate and each centriole moves to

opposite poles of the cells. Nuclear membrane and

nucleolus start to disappear.

B. Metaphase : Nuclear membrane completely

disappears in metaphase. Chromosomes complete

their condensation and become clearly visible

along with their sister chromatids. All chromosomes

are arranged parallel to equatorial plane (central

plane) of the cell. Special type of flexible protein

fibers (spindle fibers) are formed between

centromere of each chromosome and both centrioles.

C. Anaphase : In anaphase, centromeres split and

thereby sister chromatids of each chromosome

separate and they are pulled apart in opposite

directions with the help of spindle fibers. Separated

sister chromatids are called as daughter

chromosomes. Chromosomes being pulled appear

like bunch of bananas. In this way, each set of

chromosomes reach at two opposite poles of the

cell.

D. Telophase : The chromosomes which have reached at opposite poles of the cell now

start to decondense due to which they again become thread-like thin and invisible. Nuclear

membrane is formed around each set of chromosomes reached at poles. Thus, two daughter

nuclei are formed in a cell. Nucleolus also appears in each daughter nucleus. Spindle

fibers completely disappear.

In this way, karyokinesis completes and cytokinesis

begins.

The cytoplasm divides by cytokinesis and two

new cells are formed which are called as daughter

cells. In this process, a notch is formed at the equatorial

plane of the cell which deepens gradually and thereby

two new cells are formed. However, in case of plant

cells, instead of the notch, a cell plate is formed exactly

along midline of the cell and thus cytokinesis is

completed.

Mitosis is essential for growth of the body. Besides, it is necessary for restoration of

emaciated body, wound healing, formation of blood cells, etc.