cell cycle regulation

Which of the following correctly describes cells that are in the G₀ phase?

• Mature nerve and muscle cells are unable to divide and are permanently in G₀.

• Many cells enter G₀ when they reach the checkpoint during the M phase.

• Cells in G₀ are growing and preparing for cell division.

• DNA replication occurs during G₀.

In which stage of the cell cycle are cells most susceptible (likely to experience) to mutations?

• G1

• S

• G2

• G0

Which of these may be assessed by various proteins during a "checkpoint"? CHECK ALL THAT APPLY

• Ensure that all chromosomes have lined up in the center of the cell before sister chromatids separate

• Ensure that spindle fibers have attached to all centromeres before cell division

• Ensure that DNA has been replicated properly

Which of these is a risk factor for developing cancer? CHECK ALL THAT APPLY

• growing older

• genetic inheritance

• exposure to carcinogens (toxins that can damage DNA)

• smoking

The normal function of a tumor suppressor gene is 

• to produce growth signals
• to code for proteins that inhibit, or slow, cell division
• to cause the cell to move faster through the cell cycle
• to attack cancer cells in the body

Which of the following ensure that your cells will divide properly and maintain tissue homeostasis? CHECK ALL THAT APPLY!

• proto-oncogenes & tumor suppressor genes

• DNA repair system

• apoptosis

• mutations

Cancer is...

• Uncontrolled cell growth

• Normal cell growth

• A protein

• A cell cycle regulator

A substance that is known to cause cancer is called a

• carcinogen

• retrovirus

• pathogen

• paramecium

What is Apoptosis?

• A tumor

• A protein

• Programmed cell death

• Cell cycle checkpoints

Which of the following is a type of protein that regulates the cell cycle? 

• actin 
• myosin 
• cyclin 
• pepsin