Instructor: John Godwin, Fall 2000

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This exam has 8 pages; 14 short answer and 26 multiple choice questions. Please check that your copy is complete.

If you are wearing a baseball cap, please take it off or turn it backwards.

Terminology/short answer (1 pt. Each except where noted; 25 pts total for this section) - these questions require only terms or brief answers.

1. Using a simple solid line for air and a dashed line for the blood, illustrate the concentrations of oxygen (on the axes labeled 'A' ) and carbon dioxide (on the axes labeled 'B') as air and blood pass through the lungs of a bird. Recall for your answer that air enters the bird lung from the back. (3 pts)

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

2. Very briefly, what is the basic physical reason (i.e., defined by the physics/chemistry of the world in which we live) that we need to have a respiratory pigment like hemoglobin?


- Water holds very little water (low solubility so little can dissolve in it)

3. Briefly, give three ways that the structure and function of the gills of a fish are adapted to maximize exhange of respiratory gases? (3 pts)


- Short diffusion distance: very thin epithelium

- Large surface area: structure of gill enhances this

- Maintenance of diffusion gradients: Countercurrent exchange

4. Using the axes and line for hemoglobin oxygen saturation below, show how the saturation curve would between the hemoglobin illustrated and one with a lower affinity for oxygen (draw a line illustrating this on the figure). (2 pts)

 

 
 
 
 
 
 

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5. Why does it "make sense" that antihistamines help relieve the symptoms of runny nose during a cold?


- this is an inflammation response and histamines help start this response

6. List two non-specific defenses against infection (2 pts)


Lots are possible: skin, mucous membranes, fever, iron withholding, inflammation

7. In 1796, Edward Jenner showed that exposure to the cowpox virus could provide protection (i.e., vaccinate) against the deadly smallpox virus. Which one of the key features of the immune system that we discussed does this example best represent?


- memory

8. What are the other three key features that describe immune function? Which one best accounts for the rejection of transplants that is such a problem in organ donation (circle or otherwise indicate your choice for this second part)? (2 pts)


- specificity, diversity, self/non-self recognition

9. Give the specific name of one of the two systems or compounds we discussed which can cause cells to lyse (break apart).


- complement or perforin are good here

10. If a rabbit with a bacterial infection is running a 4 degree fever (41^oC) in a 20^oC room and you drop the room temperature to 14^oC, what do you expect the rabbit's body temperature to be? Very briefly, why do you expect the temperature you list here? (2 pts)


- 41^oC

- This represents regulation at a higher level, not loss of control of temperature

11. HIV binds to the CD4 and the _ CCR5 receptor to gain entry into cells.

 

 

12. Briefly, how do the problems of ionoregulation and osmoregulation differ between a freshwater and saltwater fish ? (4 pts)


Freshwater: loss of ions and gain of water

Saltwater: gain of ions and loss of water

13. The functional unit of the vertebrate kidney is termed the __ nephron ___.
14. The key excretory organs for nitrogenous wastes in insects are termed the:

1. I am writing version ___ of this exam.
1. A
2. B
2. Most of the carbon dioxide carried by the blood in humans is carried as:
1. HCO₃^- ions in the plasma
2. CO₂ attached to hemoglobin
3. H₂CO₃ in the red blood cells
4. CO₂ dissolved in the plasma
5. HCO₃^- ions attached to hemoglobin
3. Which of the following is FALSE concerning the hemoglobin molecule?
1. It contains amino acids
2. It contains iron
3. It is composed of four polypeptide chains
4. It can bind four O₂ molecules
5. It is found in humans only
4. Breathing is usually regulated by
1. Erythropoietin levels in the blood
2. The concentration of red blood cells
3. Hemoglobin levels in the blood
4. CO₂ concentration and pH-level sensors
5. The lungs and larynx
5. Air rushes into the lungs during inspiration because
1. The volume of the thoracic cavity increases
2. Pressure in the alveoli increases
3. The diaphragm contracts and pushes upward on the chest cavity
4. Pulmonary muscles contract and pull on the outer surface of the lungs
5. Smooth muscle lining the trachea, bronchi, and bronchioles contracts and causes their volume to increase.
6. The Bohr effect on the oxygen-hemoglobin dissociation curve is produced by changes in:
1. Partial pressure of oxygen
2. Partial pressure of carbon dioxide
3. Hemoglobin concentration
4. Temperature
5. pH
7. The blood level of which gas is MOST important in controlling human respiration rate?
1. Nitric acid
2. Nitrogen
3. Oxygen
4. Carbon dioxide
5. Carbon monoxide
8. Much of the iron in our bodies travels in the blood attached to a protein called transferrin. The iron is transferred to our cells after binding to a specific transferrin receptor. The reason that iron is held and transported this way is:
1. Iron is toxic to bacteria and needs to be stored in a readily accessible form in case of infection.
2. Iron is necessary for the activation of the cytotoxic T cells and is passed along to these in the event of an infection.
3. Iron is a critical nutrient for bacteria and this limits its availability to them.
4. Free iron levels must be kept low in the blood to prevent precipitation.
9. In mammalian defenses against invading pathogens, all of these are considered nonspecific defense mechanisms EXCEPT:
1. The immune system
2. The skin
3. Mucous membranes
4. The inflammatory response
5. Antimicrobial proteins (e.g., lysozyme)
10. These cells release cytokines, which stimulate other cell types in the immune system.
1. cytotoxic T cells
2. delayed sensitivity T cells
3. helper T cells
4. supressor T cells
5. B cells
11. A doctor discovers that her patient can produce antibodies against some bacterial pathogens, but he is unable to protect himself against viral infections. The doctor suspects a disorder in her patient's:
1. B cells
2. plasma cells
3. cytotoxic T cells
4. suppressor T cells
5. macrophages
12. Which of the following is true of both T cells and B cells?
1. They produce effector cells against specific pathogens.
2. They are produced from stem cells of the bone marrow.
3. They can attack and destroy invading pathogens.
4. Both A and B are true.
5. A, B, and C are true.
13. The clonal selection theory implies that:
1. Related people have similar immune responses
2. Antigens activate specific lymphocytes
3. Only certain cells can produce interferon
4. Memory cells are present at birth
5. The body selects which antigens it will respond to.

 
 
 
 
 
 
14. Cell mediated immunity is mostly the function of:
1. T cells
2. B cells
3. Erythrocytes
4. Complement cells
5. Mast cells
15. The protection provided through transfer of antibodies from mother to fetus is an example of:
1. Active immunity
2. Passive immunity
3. Cell-mediated immunity
4. Clonal selection
5. Autoimmunity
16. Which of the following statements about antibody-mediated immunity is CORRECT?
1. It primarily defends against fungi and protozoa.
2. It is responsible for transplant tissue rejection
3. It protects the body against cells that become cancerous.
4. It is mounted by lymphocytes that have matured in the bone marrow.
5. It primarily defends against bacteria and viruses that have already infected cells.
17. HIV infection ultimately cripples the immune system primarily through destruction of which cell type?
1. Plasma B cells
2. Cytotoxic T cells
3. Helper T cells
4. Memory B cells
5. Macrophages
18. The digestion and utilization of which nutrient creates the greatest need for nitrogenous waste secretion by the kidneys?
1. Protein
2. Starch
3. Fat
4. Oil
5. Cellulose

 
 
 
 
 
 
 
 
19. The advantage of excreting wastes as urea rather than ammonia is that
1. Urea is less toxic than ammonia.
2. Urea requires less water for excretion than ammonia.
3. Urea does not affect the osmolar gradient.
4. Urea can be exchanged for Na⁺.
5. Both A and B are advantages.
20. All of the following are mechanisms of thermoregulation in terrestrial mammals EXCEPT:
1. Changing the rate of evaporative loss of heat.
2. Changing the rate of metabolic heat production.
3. Changing the rate of heat exchange by anhydrobiosis.
4. Changing the rate of heat loss by vasodilation and vasoconstriction.
5. Relocating to cool areas when too hot or to warm areas when too cold.
21. Which of the following statements abou the transfer of fluid from the glomerulus to Bowman's capsule is CORRECT?
1. It results from active transport.
2. It transfers large molecules (e.g., proteins) as easily as small ones.
3. It is very selective as to which small molecules are transferred.
4. It is mainly a consequence of blood pressure forcing-filtering the fluid.
5. It usually includes the transfer of red blood cells to the nephron tubule.
22. If you compared the maximum urine concentration of a desert mammal and a rainforest mammal, you would expect to find that:
1. The maximum urine concentration would be higher for the rainforest mammal.
2. The maximum urine concentration would be higher for the desert mammal.
3. The maximum urine concentrations would be similar for the two mammals and to those in humans.
23. A biologist discovers a new species of organism adapted to living in a deep underground cavern that provides no source of free water. The organism is eyeless and covered by fur, and it has a four chambered heart with a closed circulatory system. What excretory system adaptations to this extreme environment might the biologist expect to find?
1. Very long Malpighian tubules
2. Very short Malpighian tubules
3. Metanephridia with a large number of nephridiopores
4. Nephrons with long Loops of Henle
5. Nephrons with short Loops of Henle

 
 
24. What characteristics do ammonia, urea, and uric acid all share?
1. They are all nitrogenous wastes.
2. They all require large amounts of water for excretion.
3. They all require about the same amount of energy to produce
4. They are all equally toxic.
5. They are all produced in this kidney.
Use the diagram in answering questions 25 and 26.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Note: You could think of the environmental concentrations with "high" being equivalent to seawater and the low being more like freshwater.

25. An organism exhibiting the pattern shown by the line labeled 'A' above would be termed:
1. an osmoconformer
2. an osmoregulator
3. anhydrobiotic
4. an ionoconformer
5. A and D are correct
26. The type of response to changing osmotic concentrations in the environment shown by the line labeled 'B' above would be found in:
1. stenohaline animals
2. euryhaline animals

This appears to be due to treatment of filarial worm infections. The worms are gone, but now the IgE system causes allergies.