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Write a Note on Mitosis

Note on Mitosis

 

Mitosis is a process by which a cell divides into two cells. All organisms grow by cell division. It takes place in all parts of plants and animals.

 

It has two parts:

 

1. A) Karyokinesis (Division of Nucleus)

1. B) Cytokinesis (Division of Cytoplasm)

 

 

1. A) Kagokinesis:

 

It is the division of nucleus and has followings phases:

 

Prophase:

 

1. i) In this phase coiling of chromosomes starts and they becomes shorter and thicker.

 

1. ii) Microtubules in cytoplasm arrange to form spindle.

 

iii) In animal cells fibers originate forming a star shaped aster.

 

1. iv) Spindle fibers, centrioles and aster form mitotic apparatus.

 

1. v) In this phase nuclear membrane and nucleoli disappear.

 

1. vi) In this phase chromosomes consists of chromatids attached on centromere.

 

 

Metaghase:

 

1. i) Chromosomes arrange themselves on equator and become more visible.

 

1. ii) Chromosomes are attached on their centromere to one spindle fiber from each pole.

 

 

Anaphase:

 

1. i) Spindle fiber shrinks and becomes short.

 

1. ii) Chromatids start separating.

 

iii) Each separated chromatid doubles itself to form chromosomes of daughter cell.

 

1. iv) Chromosomes moves to their opposite poles.

 

 

Telophase:

 

1. i) Chromosomes reached to their opposite poles.

 

1. ii) They become less visible.

 

iii) The nucleoli reappear.

 

1. iv) The nuclear membrane reappears.

 

1. B) Cytokinesis:

 

 

This is the division of cytoplasm.

 

1. i) In plant cells cytoplasm divides by the formation of cell plate, which extends across the equatorial plane until the two daughter cells becomes separated.

 

1. ii) In animal cells cytoplasm divides by furrowing or inward pinching of the membrane resulting into two daughter cells. Thus two daughter cells formed are identical to their parent cell in all respect.

 

Note: In this regard, specialists in these areas, which intend to expand their professional horizons and effectively manage the work process, receive a second education. At the same time, it is important to talk about higher education not only on the resume, but also on the availability of certain knowledge and skills. It is important for students of the 5th year of higher education to pass specialized practice, and high-level specialists need work experience, which is confirmed by personal projects and real achievements. So, the first education is a kind of filter, indicated by the employer in vacancies. The second higher education is less significant, but it has the main advantage – to emphasize the advantages of the owner, if only they correspond to the sphere of his actual activity. You know, to the employer by and large, it does not matter which department you graduated from – full-time or correspondence. But you should take into account all the pros and cons of these forms of education. And if you have chosen a correspondence form, be prepared for all the pluses or minuses.