Interphase, Definition, Stages, and Significance For NEET Exam

Interphase is the phase of the cell cycle in which a cell prepares itself for division by copying its DNA and performing essential metabolic functions. Often called the "daily living" phase, this stage is when the cell absorbs nutrients, metabolizes them, and carries out its regular activities. Although it was once referred to as the "resting phase," the term was changed because the cell is actively preparing for mitosis during interphase, not just resting.

Free Study Material for NEET Preparation

Stages of Interphase

G1 Phase (Gap 1 Phase)

• The G1 phase happens right after mitosis when the daughter cells are formed.
• During this phase, the cell grows in size and gets ready to make new DNA.
• The cell starts making important proteins needed for DNA replication.
• It also restores its nucleoli (small structures inside the nucleus) and begins duplicating the centrioles, which are important for cell division.

S Phase (Synthesis Phase)

• The S phase is when the cell’s DNA is copied.
• The cell’s genetic material, or DNA, is duplicated so that each new cell will have a complete set of instructions.
• By the end of the S phase, the amount of DNA in the cell has doubled, from 2n (normal) to 4n, in preparation for mitosis.

G2 Phase (Gap 2 Phase)

• G2 is the final stage before the cell enters mitosis.
• During G2, the cell makes RNA , tubulin (a protein important for forming the cell’s structure), and other proteins needed for cell division.
• The cell also increases its energy stores by making more ATP (the cell’s energy source).
• Before the cell moves to mitosis, it checks the newly made DNA for any mistakes and fixes them if necessary.

Quiescent Stage (G0)

• Some cells, like heart cells in adults, stop dividing and enter a resting stage called the G0 phase.
• These cells are still active and perform their regular functions, but they don't divide unless they need to, like in the case of tissue repair.

Explore - NEET Online Courses by PW

Significance of Interphase

MCQs of Interphase

Q1. Interphase is also known as ——– stage and it takes about ——– % time of cell cycle.

1. Dividing, 95%
2. Dividing, 80%
3. Resting, 95%
4. Resting, 80%

Q2. The stage between two M-phases is:

1. G1-phase.
2. S-phase.
3. G2-phase.
4. Interphase.

Q3. When does RNA and protein synthesis take place during the cell cycle?

1. G1 and G2 phase
2. S phase
3. M phase
4. Cytokinesis

Answers of MCQs of Interphase