Question

Which phase of mitosis is responsible for uncoiling of chromosomes followed by nuclear membrane formation?
A. Interphase
B. Prophase
C. Metaphase
D. Anaphase
E. Telophase

Answer 1

Hint: For a cell to divide into two identical halves it is important for all the structures of cell and DNA to be in their original form so that a cell can divide properly at the end stages of mitosis.

Complete Answer:
Mitosis is a type of cell division in which a cell is divided into two new genetically identical daughter cells. It involves the division of a cell's DNA into two sets of chromosomes. Mitosis occurs in five stages: interphase, prophase, metaphase, anaphase and telophase.

Option A: Interphase is the phase of cell division where the cell grows and prepares for mitosis by replicating its DNA. Therefore, this is the incorrect option.

Option B: Prophase is the phase in which chromosomes start to condense (for their easy separation in later stages of division) and a mitotic spindle is formed. This is followed by the disappearance of nucleolus and nuclear envelope breakdown. Therefore, this is the incorrect option.

Option C: Metaphase involves the alignment of chromosomes at the metaphase plate and the cell is now ready for division. Therefore, this is the incorrect option.

Option D: Anaphase is the phase of cell division sister chromatids are separated from each other as they move towards opposite ends of the cell. This process is driven by motor proteins. Therefore, this is the incorrect option.

Option E: Telophase is the phase when the cell is completely ready to divide and is marked by re-establishment of structures like nuclear membrane and nucleoli. The chromosomes start to decondense and uncoil. Therefore, this is the correct option.

Thus, the correct option is E) Telophase.

Additional information:
- Cytokinesis which is the process of division of cytoplasm and cell contents into two cells takes place during telophase.
- During telophase the mitotic spindle also gets broken down.

Note: Telophase is the stage where the cell is near to complete its division so the reappearance of the cell's structures and return of chromosomes to its original state is essential for successful cell division.