Cell Division and Cycle Control

Which molecules act as gatekeepers for each checkpoint of the cell cycle?

• p53 gene

• cyclins and cycline-dependent kinases

• thyroid hormones

What is the purpose the the cell cycle checkpoints?

• To repair damaged cells before they enter cell division.

• To remove damaged cells from an organism.

How many cell cycle checkpoints are there?

• 1

• 2

• 3

• 4

This is the cell cycle checkpoint that makes sure DNA has been replicated correctly during S phase.

• G1 Checkpoint
• G2 Checkpoint
• M Checkpoint
• I Checkpoint

This is the cell cycle checkpoint that makes sure environmental conditions are ideal for cell survival.

• G1 Checkpoint
• G2 Checkpoint
• M Checkpoint
• I Checkpoint

This is the cell cycle checkpoint that makes sure the correct number of chromosomes are present and attached to microtubules.

• G1 Checkpoint
• G2 Checkpoint
• M Checkpoint
• I Checkpoint

A disorder in which some of the body's cells lose the ability to control growth.

• growth factor

• human growth hormone

• cancer

• tumor

Proteins that direct cells to speed up or slow down the cell cycle.

• growth factor

• human growth hormone

• cancer

• tumor

Which one of these is characteristic of cancer cells?

• They undergo apoptosis.

• They do not respond to growth inhibitors

• They respond to growth inhibitors.

Which is a function of cyclins?

• Cyclins are carbohydrates that regulate DNA replication during the mitosis phase of the cell cycle.

• Cyclins are glycoproteins that repair DNA in the beginning of cell cycle.

• Cyclins are proteins that regulate when and how often a cell divides.