Question

A somatic cell that has just completed the S-phase of its cells cycle as compared to gamete of the same species has?

• A. Twice the number of chromosomes and twice the amount of DNA
• B. Same number of chromosomes but twice the amount of DNA
• C. Twice the number of chromosomes and four times the amount of DNA
• D. Four times the number of chromosomes and twice the amount of DNA

Answer 1

The correct option is C Twice the number of chromosomes and four times the amount of DNA

• In diploid cells (somatic cells) during G1 phase, DNA content is 2C and chromosome number is 2n whereas in haploid cells (gamete) during G, phase, DNA content is 1C and chromosome number is n. S phase is marked by replication of DNA and the amount of DNA per cell is doubled i.e., it becomes 4C in somatic cells, whereas chromosome number remains the same.
• Thus, a somatic cell that has just completed S phase will have 4C DNA content but In chromosome number, while the gamete cell has 1C DNA content and n chromosome number.

So, the correct option is option C.