Question

In which phase does the spindle fibre disappear?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase

Answer 1

Hint: Mitosis is a type of cell division where one mother cell divides to produce two new daughter cells that are genetically identical to each other. In mitosis, the DNA in the nucleus of the cell is split into two equal sets of chromosomes. Mitosis occurs in phases namely prophase, metaphase, anaphase and telophase. Mitosis is essential for the growth and development of an organism.

Complete explanation:
Option A: During prophase, chromosomes become condensed and spindle fibre begins to form. The nucleolus disappears and in late prophase, the nuclear envelope breaks to release the chromosomes.
Option A is incorrect.
Option B: In metaphase, the spindle fibres capture all the chromosomes and line them up at the central plane or metaphase plate of the cell.
Option B is incorrect.
Option C:The sister chromatids are separated and dragged towards opposite ends of the cell by spindle fibres in anaphase. Each pulled chromatid is now its own chromosome.
Option C is incorrect.
Option D: In telophase, the cell division is nearly done and the mitotic spindle starts to disappear. Nucleoli and the nuclear membrane reappear. The chromosomes decondense and return to their normal state.
Option D is correct.
Correct answer: D. Telophase.

Note:
Cytokinesis is the second part of the mitotic division. Here the cytoplasmic components are separated into two daughter cells. The stages of mitosis are the same for all eukaryotes but the process of cytokinesis differs for plant cells and animal cells. In animal cells, acontractile ring made of actin filaments is formed inside the plasma membrane. These filaments form a cleavage furrow that cleaves the cell into two. This mechanism is absent in plant cells.