Cell Cycle and Checkpoints

Which molecules act as gatekeepers for each checkpoint of the cell cycle? They promote the events of the phases of the cell cycle.

• p53 gene

• cyclins and cycline-dependent kinases

• thyroid hormones

How many cell cycle checkpoints are there?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-LS1-4

What is the first checkpoint of the cell cycle?

• Mitosis checkpoint

• G₁ checkpoint

• G₂ checkpoint

When is apoptosis initiated?

• When DNA damage is repaired.

• When cells are removed from the cell cycle.

• When DNA damage cannot be repaired.

Uncontrolled cell division is stopped by...

• tumor suppressor genes
• oncogenes

Which is an example of a negative regulatory molecule that is coded by a tumor suppressor gene?

• apoptosis

• proto-oncogenes

• p53

• oncogenes

Normal cell division is regulated by...

• Proto-oncogenes
• oncogenes

p53 activates which of the following?

• Tumor suppressor genes

• cell cycle

• DNA repair proteins. However, it might also cause apoptosis.

• uncontrolled cell division

Proto-oncogenes can mutate into...

• oncogenes
• tumor suppressor genes
• DNA repair proteins

Tags

NGSS.HS-LS3-2

Oncogenes cause super-accelerated

• apoptosis
• mitosis

Tags

NGSS.HS-LS1-4