Question

Which of the following does not occur in the interphase of eukaryotic cell division?
A) Increase of ATP synthesis
B) Increase of DNA synthesis
C) Increase of RNA synthesis
D) Reduction in cell size

Answer 1

Hint: The sequence of events which occur during cell growth and cell division are collectively called cell cycle. Cell cycle completes in two steps: Interphase and M-phase or Dividing phase. Interphase is the phase of the cell cycle in which a typical cell spends most of its life and is divided into three stages.

Complete Answer:
In the phase of interphase the cell cycle spends 95% of its most life and in M-phase cell cycle spends 5% of its full life. Interphase is divided into three phases: G1 phase, G2 phase and s phase.
- G1 phase- In this part of interphase, the cell synthesizes rRNA, mRNA, ribosomes and proteins in preparation for subsequent steps leading to mitosis. The metabolic rate, synthesis of enzymes and ATP storage is high. Increases in ATP synthesis occur in this phase. Hence option A is incorrect.
- S phase- In this phase, the chromosomes replicate forming two identical copies of DNA. Increase of DNA synthesis occurs in this phase. Hence option B is incorrect.
- G2 phase- It is a period of rapid cell growth and protein synthesis during which the cell prepares itself for mitosis. In G2 phase RNA increases. Hence option C is incorrect.
- M-phase: reduction of cell size is the process of cytokinesis. Cytokinesis occurs during the M-phase and M-phase is divided by two main categories 1. Nucleus division which is known as karyokinesis 2. Division of cytoplasm known as cytokinesis. It occurs in M-phase. Hence option D is correct.

Hence option D: reduction of cell size is the correct answer.

Note: During interphase reduction of cell size does not occur instead the cell grows and DNA replicates in an orderly manner.