Q. Select the correct statements regarding S-phase of interphase I. Occurs between $G_{1}\$and$\ G_{2}$ II. DNA replication begins in the nucleus III. Centrioles duplicate in the cytoplasm IV. As DNA is doubled, number of chromosomes also doubles The option with correct statements is
A) IV and III
B) I, II, III and IV
C) II, III and IV
D) I, II and III
Explanation
S-phase is the sub-phase between $G_{1}$-phase and $G_{2}$-phase, during which DNA synthesis or replication takes place. In animal cells, during the S-phase, DNA replication begins in the nucleus and the centriole duplication in the cytoplasm. The amount of DNA per cell doubles in the nucleus. If the initial amount of DNA is denoted as 2C, then it increases to 4C. However, there is no increase in the chromosome number
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.