Disruption of the Cell Cycle

Which of the following is NOT a defense mechanism against somatic mutations?

• tumor-suppressing genes

• DNA repair enzymes and proteins

• apoptosis

• activation of genes that, when mutated or overexpressed, can promote cancer development

Cancer is a disease of uncontrolled cell division. Cancer cells behave differently than normal cells, and function incorrectly during the cell cycle. Which of these best describes how cell division irregularities might lead to cancer?

• Cancer cells become "stuck" in G1 of interphase, which causes each cell to grow excessively large.

• Cancer cells keep dividing and do not stop when overcrowded, leading to tumor formation.

• Cancer cells remain too long in the DNA Replication part of Interphase, which creates excessive copies of new cells.

• Cancer cells divide far less than normal cells, allowing each individual cell to increase in size.

Cancer cells can divide many more times than normal cells in the body before they die off. What is the best justification for this statement?

• G1 of interphase causes the enzymes that recognize cancer cells to shut down, allowing cancer to grow.

• DNA Replication multiplies the DNA of cancer cells uncontrollably.

• Tumors are caused by uncontrolled cell division, meaning that many more cells are present in tumor tissue than elsewhere within normal tissue.

• Cancer cells are known to be larger than normal cells.

Mutations in genes which regulate the cell cycle could lead to​

​

• improved cell growth
• faster healing processes
• increased lifespan
• cancer

As cancerous cells multiply uncontrollably, abnormal tissue masses form. These masses of tissue are called

• alveoli

• metastasize

• tumors

• cell bags

In the cell cycle of typical cancer cells, mutations have most likely caused

• slower growth

• uncontrolled growth

• a failure in mitosis

• a halt in cell division

Which of these changes in a cell would cause a normal cell to become an unregulated, cancerous cell?

• Any mutation that leads to an allele that is NOT increasing the fitness of the organism.

• The repair of damaged DNA.

• The tumor-suppressing gene mutates and causes premature cell death.

• Any mutation that decreases the normal activity of the genes that make tumor-suppressing proteins.

The disorder that may occur when the cell cycle is disrupted and can result in the uncontrollable division of cells within the body is called –

• multiple sclerosis

• AIDS

• .

  cystic fibrosis

• cancer

Mutations in genes which regulate the cell cycle could lead to –

• cancer

• blood poisoning

• RSV

• hepatitis

Many types of cancer cells divide rapidly due to defects in the genes that control cell division. Which phase of the cell cycle is the target of many chemotherapy agents?

• G1

• G2

• S

• M