Question

a) explain the steps in mitosis

b) what are the key differences between meiosis and mitosis

c) If the protein actin was inhibited during cell division, what could be the impact?

Answer 1

Question

a. The mitosis contain of 5 different phases:

I. Interphase: this phase is further divided into three parts. First is G1 phase where cell grow in size, followed by S phase where DNA get replicated and G2 phase where cell make required proteins required for cell division.

II. Prophase : the chromosome start to condense, nucleolar envelope disappear and mitotic spindle start to form.

III. Metaphase : chrosome align at the metaphase plate and sister chrimatids attached to spindle fibers.

IV. Anaphase: centometers split into two and sister chromatids get separated from each other.

V. Telophase: chromosomes get separated and start to decondense. Nuclear envelope reappear.

b. The difference between mitosis and meiosis are:

I. Mitosis is a equatorial division whereas meiosis is a reductional division.

II. Mitosis take place in somatic cell and meiosis take place in germ cell.

III. Mitosis result in formation of two daughter cells and meiosis result in formation of four daughter cells.

IV. The daughter cells have same number of chromosomes as present in parent cell in mitosis whereas in meiosis the chromosome is half of parent cell.

c. Actin protein is involved in cell cycle checkpoints that rectify any error during cell division. But when actin protein get inhibited the cell cycle become unregulated and lead to disease like cancer.