Fall, 1999

Exam 2

(worth ½ point each)

1) Explain why Na+ cannot penetrate a cell membrane while cholesterol can, even though cholesterol is much larger

than an individual Na+ ion.___________________________________________________________________________

_________________________________________________________________________________________________

2) Explain the term membrane receptor protein. _________________________________________________________

_________________________________________________________________________________________________

3) Briefly explain the difference between active and passive transport mechanisms in cells._____________________

_________________________________________________________________________________________________

4) When a cell membrane depolarizes, the (normally negative) voltage changes dramatically as negative and positive

ions rush to opposite sides of the membrane. Briefly explain how the cell restores a negative membrane voltage

during repolarization. ____________________________________________________________________________

5) The organelle that serves as a pathway for transport of substances through a cell is called the: _______________

_________________________________________________________________________________________________.

6) Movement of substances through the nuclear membrane is regulated by specialized gate proteins called:_______

________________________________________________________________________________________________.

7) Which of the following terms apply to epithelial cell shape types?

a. transitional; b. cuboidal; c. stratified; d. laminar; e. squamous; f. both a and b; g. a, b, and e; h. both b and c; i. all

of these

8) Identify one part of the body where simple columnar cells are found.

_____________________________________

9) Chondroitin sulfate is found in which of the following connective tissues? a. blood; b. bone; c. cartilage;

d. both a and c; e. all of these

10) Give one example of a tissue membrane. _____________________

11) Briefly explain the function of areolar tissue. ______________________________________________________________

12) Explain the function of the acrosome on the head of a sperm cell. ________________________________________

13) The dimple on a gastrula that forms the first embryonic opening is called the _______________________.

14) Identify one adult structure derived from neural crest cells. _____________________________

15) The lining of the lungs is formed from which of the following embryonic tissue types? a. ectoderm; b. neurectoderm;

c. mesoderm; d. endoderm

16) The layer of the epidermis where keratinocytes undergo extensive mitosis is called the: ___________________

17) Explain the major function of the stratum compactum of the dermis.

_______________________________________________________________________

18) Skin color is largely determined by levels of a protein pigment called: _____________________.

19) Which of the following structures are located both in the dermis and epidermis? a. keratinocytes; b. melanocytes;

c. connective tissues; d. blood vessels; e. nerves

20) The fibers that permeate through bone tissue are made of a protein called: ______________________________

21) The variety of bone cell responsible for breaking down hydroxyapatite is called a/an: _______________________.

22) Cancellous bone is primarily responsible for: a. red blood cell production; b. supporting weight;

c. containing yellow marrow; d. white blood cell production; e. both a and d

23) Briefly explain the difference between endochondral and dermal bone. _______________________________________________________________________________

_______________________________________________________________________________

24) The tunnels surrounding the blood vessels that permeate bone tissue are called: _________________________________

Answer one of the following below (worth three points)

A) Summarize the process of early human development from the fertilized egg to the neurula stage using simple drawings.

Be sure to indicate all major developmental stages. Also, in your drawings be sure to label the different embryonic tissue

types (including neurectoderm and neural crest) and how they change their position over time.

B) Using simple diagrams where helpful, explain how cell membranes become polarized (generate a negative voltage),

how they depolarize, and how this depolarization can allow the membrane to generate an electrical current that travels

down its length.