Question

Assume that onion leaf cell after completion of S Phase it skipped the next phase, but re-

entered to Interphase. The initial number of chromosomes in Onion leaf cell considered as 2n.

What would be the number of chromosomes in re-entered cell after completing the M phase?

a) 2n+0

b) 2n+n

c) 2n+2n

d) 2n+3n​

Answer 1

Answer:

Assume that onion leaf cell after completion of S Phase it skipped the next phase, but re-entered to Interphase. The initial number of chromosomes in Onion leaf cell considered as 2n.

S phase cyclins regulate progression through the cell cycle during DNA replication. ... If a cell has not properly copied its chromosomes or there is damage to the DNA, the CDK will not activate the S phase cyclin and the cell will not progress to the G2 phase.

What would be the number of chromosomes in re-entered cell after completing the M phase?

Once mitosis is complete, the cell has two groups of 46 chromosomes, each enclosed with their own nuclear membrane. The cell then splits in two by a process called cytokinesis, creating two clones of the original cell, each with 46 monovalent chromosomes.