MED100-III Cancer Characteristics Quiz

What is the primary cause of cancer according to the text?

Failure of mechanisms regulating cell proliferation

Which of the following statements about cell proliferation in adult tissues is true?

Some adult tissues undergo continuous cell proliferation, while others do not

Which of the following cells is NOT mentioned in the text as an example of cells that normally do not proliferate except during healing processes?

Skin cells

What determines the rate of growth and adult body size?

Cell birth and cell death rates Signup and view all the answers

What does the text suggest about the lifespan of intestinal epithelial cells?

They live for a few days before dying and being replaced Signup and view all the answers

What are the three broad classes of genes implicated in the onset of cancer?

Protooncogenes, tumor-suppressor genes, and genome maintenance genes Signup and view all the answers

How do mutations in protooncogenes contribute to cancer?

They cause increased gene expression or production of a hyperactive gene product Signup and view all the answers

What is the primary function of tumor-suppressor genes?

To restrain cell growth and division Signup and view all the answers

What happens when genome maintenance genes are inactivated?

Cells acquire additional genetic changes at an increased rate Signup and view all the answers

Which of the following gene products are involved in regulating cell proliferation or cell death by apoptosis?

Protooncogenes and tumor-suppressor genes Signup and view all the answers

What is the role of DNA repair genes in cancer development?

They participate in repairing damaged DNA Signup and view all the answers

What is a key characteristic of cancer cells that allows them to grow uncontrollably?

They fail to differentiate normally. Signup and view all the answers

How does angiogenesis contribute to tumor growth?

It allows the tumor to grow beyond the size of about a million cells. Signup and view all the answers

Which of the following statements about leukemic cells is true?

They are derived from a common hematopoietic stem cell in the bone marrow. Signup and view all the answers

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

Benign tumors are composed of normal cells, while malignant tumors have invading tumor cells. Signup and view all the answers

What is a key factor that contributes to the genetic instability of cancer cells?

They result from non-lethal somatic mutations. Signup and view all the answers

How do cancer cells differ from normal cells in terms of their lifespan?

Cancer cells divide indefinitely, while normal cells have a limited lifespan. Signup and view all the answers

What is responsible for resistance in some cancer cells?

Mutations in apoptosis-control genes Signup and view all the answers

Which gene expression is activated by chromosomal translocation in B cell lymphoma?

Bcl-2 Signup and view all the answers

What is the most frequent mutation in human cancers?

p53 Signup and view all the answers

Which environmental agent is known to cause a significant percentage of lung cancers?

Tobacco smoke Signup and view all the answers

What acts as a safety device in the G1 checkpoint, stopping cell division in the presence of DNA damage?

p53 Signup and view all the answers

What type of genetic damage leads to excessive cell proliferation and cancer?

Acquired mutations Signup and view all the answers

What is the primary mechanism by which loss of proapoptotic genes can occur?

Loss of both alleles Signup and view all the answers

What is the effect of a single mutation that produces a hyperactive proto-oncogene (oncogene)?

Excessive cell proliferation Signup and view all the answers

Which of the following statements about the progression of cancer is correct?

Cancer is a genetic disease, and mutations are central to its etiology and progression. Signup and view all the answers

What is the relationship between DNA repair defects and the development of cancer?

Sporadic cancer with DNA repair defects is less common than cancers without abnormal repair. Signup and view all the answers

What is the relationship between the stages of cancer evolution and the loss of tumor-suppressor genes and activation of proto-oncogenes?

Increasing degrees of abnormality are associated with sequential loss of tumor-suppressor genes from several chromosomes and activation of proto-oncogenes. Signup and view all the answers

What is the primary reason that oncogenic mutations can lead to the development of a life-threatening disease?

Oncogenic mutations allow even one mutant cell to develop into a life-threatening disease. Signup and view all the answers