Question

Question 14 Can there be mitosis without DNA replication in S phase?

Class XI Biology Chapter - Cell Cycle and Cell Division Page 172

Answer 1

Mitotic cell division cannot take place without DNA replication in S phase. Two important events take place during S phase – one is the synthesis or duplication of DNA and the other is the duplication of the centriole. DNA duplication is important as it maintains the chromosome number in the daughter cells and hence Mitosis is an equational division. Therefore, the duplication of DNA is an essential step and without it, no mitosis can take place.

Answer 2

Hello friend !!!

Here's the answer you are looking for

In the process of mitosis, at first DNA replication takes place. Then when the Chromosomes are separated after the metaphase both the newly formed cells will contain same number of chromosomes and DNA.

But if DNA replication doesnt takes place in s phase, after metaphase the chromosomes will be separated.
As a result of which each newly formed cells will get the same number of chromosomes as the parent cell but half the number of DNA as the parent cell and this is not mitosis.

In mitosis, 2 cells are formed having same the number of chromosomes and DNA as the parent cell.

Therefore, there cannot be mitosis without DNA replication in the S phase



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