11. Cell Division

The difference between benign and malignant tumors is:

a) Malignant tumors do not spread to other sites.

b) Benign tumors have not lost growth control.

c) Benign tumors have not spread to other sites.

d) Malignant tumors have not lost growth or control.

Which of the following processes do normal proto-oncogenes typically exhibit?

a) They normally suppress tumor growth.

b) They enhance tumor growth.

c) They stimulate normal cell growth and division.

d) They are underexpressed in cancer cells.

1477

rank

When activated by signals in the cell, Protein X can stop cells from growing and dividing into new cells. What type of gene codes for Protein X?

a) Oncogene.

b) Tumor-suppressor gene.

c) Protein kinase gene.

d) Protein Vesicle gene.

e) Proto-oncogene.

1120

rank

What is the difference between a benign tumor and a malignant tumor?

1192

Which of the following hypotheses is best supported by observing cancer cells in a culture?

397

A cancer cell __________.

In the human genome, oncogenes __________.

364

Most human cancers are __________.

What gene has been called the "guardian angel of the genome"?

379

Why is cancer more prevalent in older people?

416

In what way can cancer be hereditary?

317

The BRCA1 and BRCA2 genes are thought to be what type of genes?

509

What two genes are often mutated in colon cancer?

847

Which of the following accurately characterizes our current understanding of cancer development?

346

Describe three ways that cancer cells differ from normal cells.

572

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to a. disruption of mitotic spindle formation. b. suppression of cyclin production. c. myosin denaturation and inhibition of cleavage furrow formation. d.inhibition of DNA synthesis.

1700

One difference between cancer cells and normal cells is that cancer cells a. are unable to synthesize DNA. b. are arrested at the S phase of the cell cycle. c. continue to divide even when they are tightly packed together. d. cannot function properly because they are affected by density-dependent inhibition.

526

Evaluate each of the following defects. Which could lead to uncontrolled growth in cancer? Select True or False for each statement. T/F The overexpression of MPF activity. T/F A nonfunctional Rb protein. T/F The overexpression of G1 cyclin. T/F A nonfunctional E2F protein.

556

All your cells contain proto-oncogenes, which can change into cancer-causing oncogenes. Why do cells possess such potential time bombs?

503

Compare and contrast the effects of removing growth factors from asynchronous cultures of human cells that are normal and those that are cancerous.

354

Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells? a. Proto-oncogenes first arose from viral infections. b. Proto-oncogenes are mutant versions of normal genes. c. Proto-oncogenes are genetic 'junk.' d. Proto-oncogenes normally help regulate cell division.

763

Scientific Thinking The study described in Module 8.10 was purely observational; there were no controlled groups. Imagine that you are an oncologist. Design a hypothesis-driven study to determine whether mastectomy improves breast cancer survival over lumpectomy. What are your control groups? Would such a study be ethical to undertake? Why or why not?

338