Question

Which of the following occurs in somatic cell cycle?

• A. DNA replication takes place in S phase
• B. A short interphase is followed by a long mitotic phase
• C. G${}_2$ phase follows interphase
• D. In G${}_1$ phase DNA content is double the amount of DNA present in the original cell

Answer 1

The correct option is A DNA replication takes place in S phase

In the somatic cell cycle, DNA replication takes place in S phase. The goal of this process is to create exactly two identical semi-conserved chromosomes. The cell prevents more than one replication from occurring by loading pre-replication complexes onto the DNA at replication origins during G${}_1$ phase which are dismantled in S phase as replication begins. In synthesis, the enzyme helicase unwinds the DNA double helix, and the enzyme polymerase re-binds free-floating nucleotides to the separate DNA single strands in accordance with the complementary base pairing rule.

So, the correct answer is option A.