Question

In a cell, the initial amount of DNA is 2C and the cell has 2n number of chromosomes at G${}_1$. What will be the amount of DNA and number of chromosomes after S phase?

• A. 2C and 4n respectively
• B. 4C and 4n respectively
• C. 4C and 2n respectively
• D. 2C and 2n respectively

Answer 1

The correct option is C 4C and 2n respectively

During S phase, DNA synthesis or replication takes place. In this time the amount of DNA per cell doubles. However, there is no increase in the chromosome number and the chromosome number remains same. Hence, the amount of DNA and number of chromosomes after S phase will be 4C and 2n respectively.