Instructor: John Godwin, Fall 1998

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This exam has 8 pages. Please check that your copy is complete

Terminology/Short Answer (1 pt. each except where noted) - these questions require only terms or short answers. Answer in the spaces provided.

1. Imagine you are working in the yard and have just poked your finger with a splinter of wood. List, briefly, the three things which now happen to begin the inflammation response (3 pts)
1. Release of histamines (and prostaglandins)
2. Vasodilation
3. Invasion of tissue by monocytes (which become macrophages) and other white blood cells
2. If you are exposed to carbon monoxide, you can literally die from lack of oxygen even when oxygen concentrations are quite high in the air you are breathing. Briefly, why is this?


Carbon monoxide binds hemoglobin and prevents oxygen from binding. Without hemoglobin being able to bind oxygen, blood can carry very little O₂.
 

3. List one physical reason associated with differences between water and air (of the three that we talked about) that explains why the gas exchange system of insects would not work for an aquatic arthropod like a crayfish.

Water holds much less O2 than air
O2 diffuses very slowly through water
Water is very dense relative to air (and therefore harder to move)
 
4. What is the term for an animal that allows the water concentration in its tissues to match the water concentration of its environment?

Osmoconformer
5. What are bird droppings mainly composed of and why does this make them so difficult to wash off your windshield?


- Bird droppings are largely uric acid. This compound is nearly insoluble in water.
 

6. What is the term for the specific type of lung that birds have?


Parabronchial
 

7. What is the clinical significance of the fact that some individuals lack a functional CCR5 chemokine receptor because they are missing a stretch of 32 nucleotides in this gene?


- HIV binds to this receptor (and the CD4 receptor); these individuals cannot become infected due to this receptor difference.
 

8. Transferrin is an iron-binding protein found in high abundance in blood. Briefly, why might it be beneficial to have such a protein in the body from the perspective of fighting infection?


- Iron is a critical limiting nutrient for bacteria. Binding it to a protein like this keeps bacteria from obtaining and using it.
 

9. Which two hormones are released in the posterior pituitary in mammals?

1. The nitrogenous waste an animal uses can very often be predicted by its habitat and osmoregulatory challenges. Imagine a toad living in the desert without free access to water. Which particular nitrogenous waste would you predict this species would use?
1. ammonia
2. uric acid
3. nitric acid
4. all of the above
5. none of the above
2. Air rushes into the lungs of humans 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. smooth muscle lining the trachea, bronchi and bronchioles contracts and causes their volume to increase
5. pulmonary muscles contract and pull on the outer surface of the lungs
3. Most of the Carbon dioxide in the blood of humans is transported
1. as dissolved CO₂ in plasma
2. as bicarbonate ion in plasma
3. attached to hemoglobin in red blood cells
4. attached to hemoglobin in plasma
5. as carbonic acid
4. Breathing rate is usually regulated by:
1. erythropoetin levels in the blood
2. the concentration of red blood cells
3. hemoglobin levels in blood
4. CO₂ concentrations in blood and effects on blood pH
5. the lungs and larynx

 
 
 
 
 
 
5. Diagrams A-E below show respiratory gas concentrations in both the respiratory medium and in blood along the length of a gas exchange organ. The concentrations in blood are shown by a dashed line while the concentrations in the respiratory medium are shown by a solid line. Which of the diagrams A-E correctly depicts the concentrations of oxygen along the length of a bird lung? Remember that air enters at the back of a bird lung.
1. a
2. b
3. c
4. d
5. e
6. Which of the diagrams A-E correctly shows the concentrations of carbon dioxide along the length of a bird lung?
1. a
2. b
3. c
4. d
5. e
7. Which of the diagrams A-E correctly shows the concentrations of oxygen along the length of a fish gill?
1. a
2. b
3. c
4. d
5. e



 
 
 
 

8. Which of the following is a necessary adaptation for a mother to supply her fetus with oxygen?
1. the affinity of her hemoglobin for oxygen must increase during early pregnancy
2. fetal hemoglobin must have a greater affinity for oxygen than does maternal hemoglobin
3. the fetus must synthesize myoglobin during early development
4. the pH of maternal blood must be as high as possible
5. the blood types of mother and fetus must be compatible
9. All of the following respiratory surfaces are associated with capillary beds EXCEPT the:
1. gills of fishes
2. alveoli of the lungs
3. tracheae of insects
4. skin of earthworms
10. The phenomenon that increases the efficiency of gas exchange at fish gills is the
1. counter current exchange mechanism
2. co-current exchange mechanism
3. high degree of oxygen saturation of water
4. back-and-forth movement of water that maximizes oxygen uptake
5. very high blood pressure found in the circulatory system of fishes
11. Select the formula below that correctly represents the behavior of CO₂ in the blood.
1. CO₂ + H₂0 ù H₂CO₃ + CO
2. CO₂ + H⁺ ù HCO₃⁺ ù H₂0 + H₂CO₃
3. CO₂ + HCO₃^- ù H⁺ ù H₂0 + H₂CO₃
4. CO₂ + H₂0 ù H₂CO₃ ù HCO₃^- + H⁺
5. CO₂ + H₂CO₃ + O₂ ù H₂0 + CO₂ + H₂CO₃
12. Which of the following statements is FALSE concerning the hemoglobin molecule?
1. it contains amino acids
2. it contains iron
3. it is composed of four subunits
4. it can bind four oxygen molecules
5. it is found only in humans
13. Which one of the following statements about gills operating in water is FALSE?
1. water can support delicate gill features
2. most fish actively pump water over their gills
3. keeping membranes moist is no problem
4. water carries more oxygen than air and therefore makes gills more efficient than lungs
5. gills have evolved many times in aquatic animals
14. What are antigens?
1. proteins found in the blood that cause foreign blood cells to clump
2. proteins embedded in B-cell membranes
3. proteins that consist of two light and two heavy chain polypeptide chains
4. antibody-generating foreign molecules
5. both a and c are correct
15. The clonal selection theory is an explanation for
1. how a single type of stem cell can produce both red blood cells and white blood cells
2. how antibody proteins can be molded to fit antigens after the antigen interacts with the antibody-producing type of cell
3. how an antigen can induce the multiplication of very few cells to result in production of high levels of specific antibodies
4. how HIV can disrupt the immune system
5. how macrophages can recognize specific T cells and B cells
16. 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 all true
17. The MHC (major histocompatibility complex) is important in
1. distinguishing self from non-self
2. recognizing parasitic pathogens
3. identifying bacterial pathogens
4. identifying abnormal cells
5. both a and d are correct
18. Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected?
1. no urine would be produced
2. a less-than-normal volume of urine which was less concentrated than the blood (hypotonic) would be produced
3. a greater-than-normal volume of urine equal in concentration to the blood (isotonic) would be produced
4. a greater-than-normal volume of urine that was more concentrated than the blood (hypertonic) would be produced
19. A biologist discovers a new species of organism in an underground cavern with no access to free water. This organism is eyeless, covered with fur, has a four chambered heart, and has a closed circulatory system. Based on this description, what type of excretory system would you expect to find in this animal?
1. very long Malpighian tubules
2. very short Malpighian tubules
3. protonephridia with large nephridiopores
4. kidneys with long Loops of Henle
20. Which pair of water and ion problems listed below are those faced by a marine fish?
1. loss of water and gain of ions
2. loss of water and loss of ions
3. gain of water and loss of ions
4. gain of water and gain of ions
5. the problems are identical to those faced by a freshwater fish.
21. Sharks are also marine animals. The rectal gland of a shark is an adaptation to which of the following problems:
1. loss of ions
2. gain of ions
3. loss of water
4. gain of water
5. both a and c are correct
22. Malpighian tubules are the excretory organs found in:
1. earthworms
2. flatworms
3. jellyfish
4. insects
5. vertebrates
23. Which part of the vertebrate nephron consists of capillaries?
1. glomerulus
2. loop of Henle
3. collecting duct
4. proximal convoluted tubule
24. All of the following are functions of the mammalian kidney EXCEPT
1. water retention
2. filtration of blood
3. excretion of nitrogenous waste
4. regulation of salt balance in the blood
5. production of urea as a waste product of protein catabolism
25. Which of the following statements about the transfer of fluid from the glomerulus to Bowmanâs capsule is CORRECT?
1. it results from active transport
2. it transfers large molecules 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 force-filtering the fluid
5. it usually includes the transfer of red blood cells to the nephron tubule
26. All of the following are mechanisms of thermoregulation in ectothermic animals EXCEPT
1. countercurrent heat exchangers
2. changing the rate of heat production by activity
3. changing the rate of heat loss by vasodilation and vasoconstriction
4. relocating to cool areas when too hot or warm areas when too cold
5. insulation influencing the rate of heat loss or gain

 
 
 
 
 
 

Questions 27 through 29 refer to the diagram below showing the action of a hormone and inositol triphosphate.
 
 

27. Guanosine triphosphate is represented in the diagram by number
1. 1
2. 2
3. 3
4. 4
5. 7
28. Calcium, the third messenger, is represented by number
1. 2
2. 3
3. 4
4. 5
5. 8
29. The substance represented by number 4 is:
1. a G protein
2. phospholipase C
3. protein kinase
4. adenosine monophosphate
5. adenylyl cyclase
30. Which of the following statements about hormones is CORRECT?
1. steroid and peptide hormones produce different effects, but use the same biochemical mechanisms
2. steroid and peptide hormones produce the same effects, but differ in the mechanisms that produce the effects
3. steroid hormones may affect the synthesis of proteins, whereas peptide hormones affect the activity of proteins already present in the cell.
4. steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA
5. steroid hormones affect the synthesis of proteins to be exported from the cell, whereas peptide hormones affect the synthesis of proteins that remain in the cell
31. Fever represents a failure of thermoregulation in endothermic animals.
1. This statement is true
2. This statement is false
32. The reason(s) that the body has such difficulty combatting HIV infection and preventing progression to AIDS
1. HIV mutates quickly
2. HIV primarily targets T helper cells
3. HIV blocks antigen recognition by macrophages
4. A and B are correct
5. B and C are correct