Question

Study the diagram given below which represents a stage during the mitotic cell division answer the questions that follow:

(i) Identify the stage giving suitable reasons.

(ii) Name the parts numbered A and B.

(iii) What is the technical term for the division of the nucleus?

(iv) Mention the stage that comes before the stage shown in the diagram. Draw a neat labeled diagram of the stage mentioned.

(v) Which is the cell division that results in half the number of chromosomes in daughter cells?

Answer 1

(i) Identification of the stage

1. The given diagram represents the anaphase stage of mitotic division.
2. In the diagram, each chromosome has split and the two sister chromatids are moving to opposite poles.
3. These key events are observed during the anaphase stage.

(ii) Naming of parts A and B

1. Part A: In the diagram, part A indicates centriole.
2. Part B: In the diagram, part B indicates chromatids.

(iii) Technical term

1. The technical term for the division of the nucleus is karyokinesis.
2. Karyokinesis involves four stages- prophase, metaphase, anaphase, and telophase.

(iv) Stage before the diagram

1. The stage that comes before anaphase is known as metaphase.
2. In the metaphase stage, the chromosomes are aligned at the equatorial plate through spindle fibers to both poles.

Diagram of metaphase stage:

(v) Meiosis:

1. The cell division called meiosis results in half the number of chromosomes in daughter cells.
2. Meiosis is responsible for gamete formation in sexually reproducing organisms. It also maintains the chromosome number in a species.