Question

What can trigger arrest during the cell cycle?

A) Accumulation of cyclins; insufficient growth factors.
B) Decreased DNA damage; proper spindle fiber attachment.
C) Reduced cell size; absence of checkpoint proteins.
D) Enhanced cell signaling; increased ATP production.

Answer 1

The correct trigger that can arrest the cell cycle is A) Accumulation of cyclins; insufficient growth factors, owing to the role of cyclins, Cdks, and growth factors' influence on cell cycle regulation.

Step-by-step explanation:

Triggers for arrest during the cell cycle can include internal checks such as accumulation of cyclins and the regulation through cell checkpoints by various molecular signals like cyclin-dependent kinases (Cdks) and tumor suppressor proteins. These systems ensure the cell is ready for the next phase, whether it be DNA replication or chromatid separation during mitosis. Arrest can also be caused by external factors such as insufficient growth factors, cell size, and the influence of hormones like human growth hormone (HGH).

Answer A) Accumulation of cyclins; insufficient growth factors, is correct in this context. Cyclins and Cdks are internal regulators of the cell cycle checkpoints that can trigger an arrest if there is an accumulation or abnormal function, and insufficient growth factors are an external signal that can initiate or inhibit the cell cycle. Consequently, a mutation in cyclin-dependent kinase would likely result in a failure to properly control cell division, leading to potential over-proliferation of cells, which is a hallmark of cancer biology.