Question

the diagram below represents the cell cycle
when cells leave the cell cycle, they exit during g₁ phase and then enter g₀ phase, a resting period. most normal cells can leave g₀ phase and reenter the cell cycle at g₁ phase before entering s phase. cancer cells are different because they cannot enter g₀ phase and are likely to do which of the following?
die after completing mitosis
mutate during g1 phase
fail to complete s phase
repeat the cell cycle continuously

Explanation:

Cancer cells are characterized by uncontrolled cell division. Since they cannot enter the \(G_0\) (resting) phase, they keep cycling through the cell cycle ( \(G_1\), \(S\), \(G_2\), mitosis) without proper regulation. Normal cells can pause in \(G_0\), but cancer cells bypass this check - point.

• Option 1: Cancer cells do not die after mitosis; they keep dividing.
• Option 2: Mutation is a cause of cancer (not a result of not entering \(G_0\) in the context of this question).
• Option 3: Cancer cells can complete \(S\) phase (DNA synthesis) as they are actively dividing.
• Option 4: Since they skip \(G_0\) (a resting phase), they repeat the cell cycle continuously.

Answer:

Repeat the cell cycle continuously.