cellb u19

Question 1

What are the two defining properties of cancer cells?

Answer 1

(1) Proliferate in defiance of normal signals, and (2) invade/colonize other tissues.

Question 2

What is the difference between benign and malignant tumors?

Answer 2

Benign = stay in one place; malignant = invade tissues + spread (metastasize).

Question 3

What is metastasis?

Answer 3

Cancer cells break away from the original tumor, enter blood/lymph, and form secondary tumors.

Question 4

What is epidemiology?

Answer 4

The study of environmental/lifestyle factors that correlate with disease (e.g., smoking, HPV).

Question 5

HPV infection increases risk of which cancer?

Answer 5

Cervical cancer.

Question 6

What are passenger mutations?

Answer 6

Mutations in cancer genes that do not contribute to cancer development.

Question 7

What are driver mutations?

Answer 7

Mutations that directly promote cancer development (usually at least 3 needed).

Question 8

Why does cancer risk increase with age?

Answer 8

Mutations accumulate over a lifetime due to replication errors and environmental mutagens.

Question 9

What is genetic instability?

Answer 9

A condition where cells accumulate mutations rapidly due to defective repair/checkpoints.

Question 10

What are examples of genetic instability?

Answer 10

Chromosomal deletions, duplications, inversions, translocations, aneuploidy.

Question 11

Why do cancer cells have a competitive advantage?

Answer 11

Mutations allow them to proliferate, survive stress, and avoid apoptosis

Question 12

What does loss of p53 cause?

Answer 12

Cells fail to stop division after DNA damage → no apoptosis → survival of damaged cells.

Question 13

Why do cancer cells proliferate indefinitely?

Answer 13

They reactivate telomerase, maintaining telomere length and avoiding senescence.

Question 14

Why are cancer cells abnormally invasive?

Answer 14

They lose adhesion molecules that normally keep cells in place

Question 15

Why do cancer cells consume more glucose?

Answer 15

They need high ATP to support rapid proliferation (Warburg-like effect).

Question 16

: What is an oncogene?

Answer 16

A gain-of-function mutant gene that is always active and pushes the cell to divide.

Question 17

What is a tumor suppressor gene?

Answer 17

A gene that normally prevents cell proliferation; cancer arises after loss-of-function.

Question 18

What is the APC gene and its role in colorectal cancer?

Answer 18

APC is a tumor suppressor that inhibits Wnt signaling. Loss → polyps → colon cancer.

Question 19

Why is cancer treatment difficult to develop

Answer 19

Cancer cells mutate rapidly → high genetic diversity → fast resistance → late detection.

Question 20

How does imatinib (Gleevec) treat cancer?

Answer 20

Blocks a hyperactive oncogenic tyrosine kinase (e.g., in chronic myeloid leukemia).