Question

model 3 – radiation

1. according to model 3, ultraviolet light is affecting a cell in which phase of the cell cycle?
2. ultraviolet light may cause dna damage, which is known as a mutation. how might such damage affect events taking place during the synthesis phase? hint: use information from model 2.

Explanation:

1. The diagram shows ultraviolet light directed at the segment labeled $G_1$ of the cell cycle.
2. During the synthesis (S) phase, DNA is replicated. UV-induced DNA damage (mutations) will be copied during this replication, leading to the damaged DNA sequence being passed to the daughter cells. Additionally, the cell may activate DNA repair mechanisms during S phase to fix the damage, which could slow or halt replication if the damage is severe.

Answer:

1. $G_1$ phase
2. UV-induced DNA damage will be replicated during the S phase, passing mutations to daughter cells; the cell may also trigger DNA repair processes that can delay or stop DNA synthesis.