Question

1.4.2 test (cst): heredity
question 22 of 25
a cell must pass which step of the cell cycle before it begins the process of dna replication?
a. g₂ checkpoint
b. g₁ checkpoint
c. mitosis
d. s phase

Explanation:

The cell cycle has checkpoints. The G₁ checkpoint is before DNA replication (S - phase). It checks for cell size, nutrients, growth factors, and DNA damage. If passed, the cell enters S - phase for DNA replication. G₂ checkpoint is after S - phase. Mitosis is after DNA replication. S - phase is when DNA replication occurs, not before.

Answer:

B. G₁ checkpoint