Question

Briefly describe the events that occur in each phase of interphase.

Short answer

Interphase of a cell cycle has 3 phases namely- G1 phase, S phase, G2 phase

Step-by-step solution

Introduction

The cell cycle consists of two phases- interphase and mitotic phase.During interphase, the cell shows growth and DNA is replicated. After Interphase, the mitotic phase starts. During this phase, the duplicated chromosomes come together and are transported into the nucleus of the daughter cell. After mitosis, Cytokinesis occurs, where the cytoplasm is divided , forming two identical daughter cells from a single parent cell.

Explanation

Interphase is referred as the preparatory phase of the cell cycle. In this phase, the cell prepares for the upcoming mitosis and executes normal growth processes. It is the longest phase of the cell division process. Interphase is divided into 3 subphases-

• G1 phase,
• S phase,
• G2 phase

1. G1 Phase (First Gap phase):

It is the first stage of interphase. In this phase, very little change is found.

During this G1 stage, the cell becomes metabolically active. The cell starts to accumulate the required materials to make the DNA and proteins. Along with this, it also accumulates sufficient energy which is required for the DNA replication in the nucleus.

2. S Phase ( DNA Synthesis phase ):

In this stage, DNA synthesis takes place. During S phase, for each and every cell , DNA count becomes twice , but the chromosome number remains unchanged.

3. G2 Phase (Second Gap phase):

In this phase, the cell replenishes the used energy stores and also synthesizes different proteins and RNA required for further chromosomal activities. Some cell organelles like mitochondria also grows and gets duplicated during this phase. The cytoskeleton is also disassembled to supply resources for the mitosis.