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Multiple Choice
In what phase do cells make a copy of their chromosomes before mitosis starts?
A
G1 phase
B
M phase
C
S phase
D
G2 phase
Verified step by step guidance
1
Understand the cell cycle, which consists of interphase and the mitotic phase. Interphase is further divided into G1, S, and G2 phases.
Recognize that during the cell cycle, the cell prepares for division by growing and replicating its DNA.
Identify that the S phase, or synthesis phase, is the part of interphase where DNA replication occurs. This is when the cell makes a copy of its chromosomes.
Differentiate between the phases: G1 is the first gap phase where the cell grows, S phase is where DNA is synthesized, G2 is the second gap phase where the cell prepares for mitosis, and M phase is where mitosis and cytokinesis occur.
Conclude that the correct phase for chromosome replication before mitosis is the S phase, as this is when the cell duplicates its DNA to ensure each daughter cell receives an identical set of chromosomes.