Question

1. Gap junctions ________.

a. are formed by claudins and occludins

b. allow ions & small molecules to pass between cells

c. are attached to microtubules

d. anchor epithelial cells to underlying basal lamina

2. Mutation of a single ‘cancer’ gene is sufficient to convert a normal cell into a cancer cell.

True

False

3. Oncogenes are generated by loss of function mutations in proto-oncogenes

True

False

4. Fibrous structural proteins of the extracellular matrix are embedded in gels formed from polysaccharides called

glycosaminoglycans (GAGs).

Elastin

Fibronectin

laminin

5. ________ are a major family of calcium-dependent cell-surface adhesion molecules.

Fibronectins

Cadherins

Calmodulins

Calsequestrins

6. Sonic Hedgehog (Shh) is expressed in the notochord and floorplate and patterns the ventral neural tube.

True

False

7. Netrin only functions as a chemoattractant for axon growth.

True

False

8. Mammalian embryonic stem cells are cultured from cells taken from the

inner cel mass

4-cell embryo

amnion cells

trophoblast cells

9. Therapeutic cloning requires nuclear transplantation, whereas reproductive cloning does not.

True

False

10. A malignant tumor is more dangerous than a benign tumor because

		it causes neighboring cells to stop growing.
		its cells invade other tissues.
		its cells are proliferating faster.
		its cells grow bigger than normal cells.

Answer 1

1. Gap junctions allow ions and small molecules to pass between cells.
2. Mutation of a single cancer gene is sufficient to convert a normal cell into a cancer cell. True
3. Oncogenes are generated by loss of function mutations in proto-oncogenes. True
4. Fibrous structural proteins of the extracellular matrix are embedded in gels formed from polysaccharides called Glycosaminoglycans or GAGs.
5. Cadherins are a major family of calcium-dependent cell-surface adhesion molecules.
6. Sonic Hedgehog is expressed in the notochord and the floorplate and patterns the ventral neural tube. True
7. Netrin only functions as a chemoattractant for axon growth. True
8. Mammalian embryonic stem cells are cultured from cells taken from the Inner cell mass.
9. Therapeutic cloning requires nuclear transplantation, whereas reproductive cloning does not. True
10. A malignant tumor is more dangerous than a benign tumor because its cells are proliferating faster and its cells invade other tissues.