Q.Why is interphase described as a preparatory phase?

DNA replication occurs in the S phase, so the answer is (D).

Interphase has three sub-phases:

• G1 phase — the cell grows and carries out its functions; DNA amount is unchanged.
• S (synthesis) phase — DNA replicates so that each chromosome now has two sister chromatids; the DNA content doubles. …

DNA replication happens during the S (Synthesis) phase of interphase, between G1 and G2.

The cell cycle is divided into Interphase (G1, S, G2) and M-phase (mitosis/meiosis). Interphase, often called the "resting phase," is actually the busiest metabolic phase:

• G1 phase: the cell grows and prepares metabolically for DNA synthesis; DNA is NOT yet replicated.
• S phase: DNA replication occurs — the amount of DNA per cell doubles (from 2C to 4C), though chromosome number stays the same, since each chromosome now consists of two sister chromatids. In animal cells, the centriole also duplicates in the S phase. …

Anaphase belongs to M phase, not interphase.

Interphase comprises G1 (first gap), S (DNA synthesis) and G2 (second gap). Anaphase is a phase of mitotic division (M phase) during which sister chromatids move to opposite poles, so it is NOT pa …

Chromosome number does not change during S phase -- only DNA content per chromosome doubles.

The cell cycle is divided into interphase (G1, S, G2) and M phase (mitosis). During G1, the cell has its normal diploid chromosome number with each chromosome consisting of a single DNA molecule (one chromatid). During S (synthesis) phase, DNA replication occurs: each chromosome's DNA is copied, so each chromosome now consists of two sister chromatids joined at the centromere. Crucially, this does NOT create new, separate chromosomes -- the chromosome NUMBER stays exactly the same (36 here); only the DNA content doubles (and the chrom …

DNA is replicated only during the S phase of the cell cycle.

Interphase, the 'resting' phase between two successive M phases, is itself divided into three phases: G1 (Gap 1, cell grows and prepares for DNA synthesis), S (Synthesis, DNA replication occurs -- each chromosome's DNA content doubles, though chromosome NUMBER stays the same, now as two sister chromatids per chromosome), and G2 (Gap 2, the cell continues to grow and prepares for mitosis, synthesising proteins needed for cell division). DNA replication is strictly conf …

DNA replication occurs during the S (Synthesis) phase of interphase.

The cell cycle is divided into Interphase (G1, S, G2) and M phase (mitosis/meiosis). During the S phase, the amount of DNA per cell doubles as each chromosome replicates to form two sister chromatids, although the chromosome number itself does not change at this stage. T …

Interphase (G1, S, G2) is when the cell grows, duplicates organelles, and precisely replicates its DNA in preparation for the next division.

Interphase is the interval between the end of one mitotic/meiotic division and the beginning of the next. Although it is sometimes loosely called the 'resting phase', the cell is in fact extremely metabolically active during this time. Interphase is divided into three sub-phases: G1 phase (Gap 1) — the cell grows in size and synthesizes RNA and proteins needed for DNA synthesis; S phase (Synthesis) — the amount of DNA per cell doubles as DNA replication takes place (the centriole also duplicates in animal cells); a …