Final answer:
The correct sequence preceding the re-formation of the nuclear envelope during M phase in animal cells is:
- Disassembly of the nuclear envelope
- Formation of the mitotic spindle
- Condensation of chromosomes
- Separation of sister chromatids
Therefore, the correct sequence is B, C, A and D.
Step-by-step explanation:
During the M phase (mitosis) of the cell cycle in animal cells, several events occur to ensure accurate cell division. The correct sequence of events leading to the re-formation of the nuclear envelope is as follows:
- Disassembly of the nuclear envelope: The first step involves the breakdown of the nuclear envelope, allowing the cellular components to access the chromosomes.
- Formation of the mitotic spindle: Subsequently, the mitotic spindle, composed of microtubules, forms and aligns the chromosomes in preparation for their separation.
- Condensation of chromosomes: As the spindle apparatus is established, chromosomes condense, becoming more visible and distinct.
- Separation of sister chromatids: Finally, the sister chromatids are pulled apart and move toward opposite poles of the cell.
After these events, the nuclear envelope re-forms around the separated sets of chromosomes in each daughter cell.
Therefore, the correct sequence is B, C, A and D.
Your question is incomplete, most probably the complete question is:
Which of the following precede the re-formation of the nuclear envelope during M phase in animal cells?
a) Condensation of chromosomes
b) Disassembly of the nuclear envelope
c) Formation of the mitotic spindle
d) Separation of sister chromatids