Question

Explain Mitosis and phases​

Answer 1

Hola!!

Mitosis:

The type of cell division that involves the production of gametes is known as mitosis.

Phases Of Mitosis Include-

(1) Interphase

It is a resting phases as no visible changes occur in chromosomes but it is quite active in the synthesis of DNA.

(2) Prophase

• Chromatin Fibre condenses to form coiled chromosomes
• Centrosome divides into Two sister centrioles and move the opposite poles
• chromosomes attach themselves to spindle fibres
• Nuclear membrane starts disappearing
• Nucleolus disappears

(3) Metaphase

• Chromosomes line up in an equatorial plane

(4) Anaphase

• Chromosomes divide into sister chromatids from centromere
• sister chromatids reach the opposite poles
• a furrow stars forming in the cell membrane

(5) Telophase

• the furrow deepens and finally two daughter cells are formed
• nuclear membrane and nucleolus reappear
• centrioles combine to firm centrosome
• Chromosomes changed into chromatin fibre

Answer 2

Question : Explain Mitosis and phases.

Answer :

There are two types of cell division as Mitosis and Meiosis.

Mitosis :

Somatic cells and stem cells divide by mitosis. Mitosis is completed through 2 main steps. Those two steps are Karyokinesis (nuclear membrane) and cytokinesis (cytoplasmic membrane).

Now, Karyokinesis is completed through 4 steps.

Let's see them step by step.

A. Prophase : In this phase, 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 the equatorial plane ( central plane of the cell ). Special type of flexible protein fibres ( spindle fibres ) are formed between centromere of each chromosome and both centrioles.

C. Anaphase :  In this phase, centromeres split and thereby sister chromatids are pulled apart in opposite directions with the help of spindle fibres. Separated sister chromatids are called as Daughter chromosomes. 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 fibres completely disappear.

In this way, Karyokinesis is completed.

Cytoplasm divides by cyrokinesis 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 plants, a cell plate is formed exactly along the midline of the cell and thus, the 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. ]

Overall, This is the process of Mitosis.

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