Question

1.What are the two main defects that lead to cancer? (select two)

A.a protein required for cell growth that gets activated when it shouldn't be

B.a deleterious mutation in a protein that normally prevents passage through the cell cycle

C.Mutations in any gene in the genome

D.Cells getting access to too many nutrients

2. What is a tumor suppressor protein?

A.A protein that normally stops or slows down the cell cycle

B.A protein that gets activated when a tumor has formed and suppresses the growth of the tumor

C.Both of these

D.Neither of these

3.What is a proto-oncogene?

A.A gene that codes for a protein that promotes passage through the cell cycle

B.A gene that codes for a tumor suppressor protein

C.Both of these

D.Neither of these

4.What is true of all cancer cells? (choose ALL correct answers)

A.They have mutations in their DNA

B.They have lost normal control of the cell cycle

C.They express functional p53 protein

D.They express DNA replication enzymes more frequently than a differentiated, non-cancerous cell

Answer 1

1. A. A protein required for cell growth that gets activated when it shouldn't be

B. A deleterious mutation ina protein that normal prevents passage through the cell cycle

Cancer is a condition characterized by abnormal and uncontrolled growth that arises due to mutations in the genes that regulate cell cycle. These mutations may involve either the promotion of cell cycle or inactivation of cell cycle suppression.This may lead to uncontrolled cell growth or loss of cells ability to undergo apoptosis.

2. A. a protein that normally stops or slows down the cell cycle

Tumor suppressor genes are normal genes the products of which regulates cell growth and proliferation. they normally act to inhibit cell proliferation and tumor development. The loss or inactivation of tumor supressor genes leads to the loss of negative regulation of cell proliferation, thereby resulting in abnormal proliferation of cells. The proper functioning of tumor suppressor genes helps to pevent cancer

3. A. A gene that encodes for a protein that promotes passage through cell cycle.

Proto oncogenes are normal genes that are involved in normal cell growth and poliferation. Proto oncoogenes when mutated forms oncogenes that leads to cancer.

It does not code for tumor suppressor protein. Tumor suppressor proteins are coded by the tumor suppressor genes

4. A. They have mutations in their DNA

B. They have lost normal control of the cell cycle

p53 is a tumor supressor protein. The inactivation of p53 can lead to the development of cancer, hence all cancers does not express a functional p53 protein