MOCK EXAM, Exam Three
1. Some nutrients are considered “essential” in the diets of certain animals because
a. Only those animals use the nutrients
b. They are subunits of important polymers
c. They cannot be manufactured by the organism
d. Only some foods contain them
2. Intracellular digestion of peptides is usually immediately preceded by which process?
a. Hydrolysis
b. Endocytosis
c. Absorption
d. Secretion
3. Foods eaten by animals are most often composed largely of macromolecules. This requires the
animals to have methods for which of the following?
a. Elimination
b. Enzymatic hydrolysis
c. Regurgitation
d. Demineralization
4. After ingestion, the first type of macromolecule to be worked on by enzymes in the human
digestive system is
a. Protein
b. Carbohydrate
c. Cholesterol
d. Nucleic acid
5. Without functioning parietal cells, which of the following would you expect for an individual?
a. Not be able to initiate protein digestion in the stomach
b. Not be able to initiate mechanical digestion in the stomach
c. Only to be able to digest fat in the stomach
d. Not be able to produce pepsinogen
6. Which of the following enzymes has the lowest pH optimum?
a. Amylase
b. Pepsin
c. Lipase
d. Trypsin
7. A hiatal hernia affects the function of the smooth muscle between the esophagus and the
stomach. The hernia would be most likely to increase the frequency of which of the following?
a. Gastric reflux
b. Premature entry of food into the duodenum
c. Excess secretion of pepsinogen
d. Increased stomach pH
8. The pH of the gastric juice of the stomach is about 2 due to the formation of HCl. Where does
this formation of HCl occur?
a. In chief cells of the stomach
b. In parietal cells of the stomach
c. In the transformation of pepsinogen to pepsin
d. In the lumen of the stomach
9. Why are cattle able to survive on a diet consisting almost entirely of plant material?
a. They are autotrophic
b. Cattle reingest their feces
c. They have cellulose-digesting, symbiotic microorganisms in chambers of their stomachs
d. Cattle saliva has enzymes capable of digesting cellulose
10. Which of the following organs is incorrectly paired with its function?
a. Stomach ---protein digestion
b. Oral cavity---starch digestion
c. Large intestine ---bile production
d. Small intestine ---nutrient absorption
11. If the atrioventricular node could be surgically removed from the heart without disrupting signal
transmission to the Purkinje fibers, what would be the effect?
a. No apparent effect on heart activity would be observed
b. Heart rate would be decreased
c. Only ventricles would contract
d. Atria & ventricles would contract at about the same time
12. Which of the following is correct for a blood pressure reading of 130/80?
1. The systolic pressure is 130
2. The diastolic pressure is 80
3. The blood pressure during heart contraction is 80
a. 1 only
b. 3 only
c. 1 & 2 only
d. 2 & 3 only
13. If, during protein starvation, the osmotic pressure on the venous side of capillary beds drop
below the hydrostatic pressure, then
a. Hemoglobin will not release oxygen
b. Fluids will tend to accumulate in tissues
c. The pH of the interstitial fluid will increase
d. Most carbon dioxide will be bound to hemoglobin and carried away from tissues
14. A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of
smooth muscle with elastic fibers, no valves. It is which of the following?
a. Vein
b. Venule
c. Artery
d. Capillary
15. The meshwork that forms the fabric of a blood clot consists mostly of which protein?
a. Fibrinogen
b. Fibrin
c. Thrombin
d. Prothrombin
16. Average blood pressure is lowest in which structure?
a. Aorta
b. Arteries
c. Arterioles
d. Vena ceva
17. Which of the following would be described as a portal system?
a. An area connecting arterioles to venules
b. A vessel or vessels connecting two capillary beds
c. A space within or between organs where blood is allowed to pool
d. A series of vessels that returns blood to the heart in an animal with an open circulatory
system
18. Which of these speed up heart rate?
a. Low density lipoproteins
b. Immunoglobins
c. Erythropoietin
d. Epinephrine
19. Which of the following features do all gas exchange systems have in common?
a. The exchange surfaces are moist
b. They are enclosed within ribs
c. They are maintained at constant temperature
d. They are exposed to air
20. Which of the following is an example of countercurrent exchange?
a. the flow of water across the skin of a frog & that of blood within the ventricle of its heart
b. the flow of water across the gills of a fish & that of blood within those gills
c. the flow of blood in the dorsal vessel of an insect & that of air within its tracheae
d. the flow of air within the primary bronchi of a human & that of blood within the pulmonary
veins
21. Air rushes into the lungs of humans during inhalation because
a. Rib muscles and diaphragm contract, increasing lung volume
b. Pressure in alveoli increases
c. Gas flows from region of lower pressure to region of higher pressure
d. Pulmonary muscles contract and pull on outer surface of lungs
22. Which of the following occurs with the exhalation of air from human lungs?
a. The diaphragm contracts
b. The epiglottis closes
c. The rib cage expands
d. The volume of the thoracic cavity decreases
23. The blood level of which gas is most important in controlling human respiration rate?
a. Nitric acid
b. Nitrogen
c. Oxygen
d. Carbon dioxide
24. The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in
a. The partial pressure of oxygen
b. The partial pressure of carbon monoxide
c. pH
d. temperature
25. How is most of the carbon dioxide transported by the blood in humans?
a. Bicarbonate ions in plasma
b. CO2 attached to hemoglobin
c. Carbonic acid in the erythrocytes
d. CO2 in the plasma
26. How does the hemocyanin of arthropods and mollsucs differ from the hemoglobin of mammals?
a. Oxygen dissociation curve for hemocyanin is linear
b. Hemocyanin carries appreciably more CO2
c. The protein of hemocyanin is not bound to metal
d. Hemocyanin has protein coupled to copper rather than iron
27. When you hold your breath, which of the following blood gas changes first leads to the urge to
breathe?
a. Rising O2
b. Falling O2
c. Rising CO2
d. Falling CO2
28. Where do air-breathing insects carry out gas exchange?
a. In specialized external gills
b. In specialized internal gills
c. In alveoli of the lungs
d. Across the membranes of cells
29. Which cells and which signaling molecules are responsible for initiating an inflammatory
response?
a. Phagocytes: lysozymes
b. Phagocytes: chemokines
c. Dendritic cells: interferons
d. Mast cells: histamines
30. If a newborn were accidentally given a drug that destroyed the thymus, what would most likely
happen?
a. His cells would lack class I MHC molecules on their surface
b. His T cells would not mature and differentiate appropriately
c. His humoral immunity would be missing
d. Genetic rearrangement of antigen receptors would not occur
31. A person exposed to a new cold virus would not feel better for one to two weeks because
a. Specific B & T cells must be selected prior to a protective response
b. It takes up to two weeks to stimulate immunologic memory cells
c. No memory cells can be called upon, so adequate response is slow
d. V-J gene rearrangement must occur prior to a response
32. These cells are involved in cell-mediated immunity, and they respond to class I MHC moleculeantigen complexes:
a. Cytotoxic T cells
b. Natural killer cells
c. Helper T cells
d. Macrophages
33. Which of the following is a pathway that would lead to the activation of cytotoxic T cells?
a. B cell contact antigen --- helper T activated ---- clonal selection appears
b. Body cell infected with a virus --- new viral proteins appear --- class I MHC molecule-antigen
complex displayed on cell surface
c. Self-tolerance of immune cells --- B cells contact antigen ---- cytokines released
d. Cytotoxic T cells ---- class II MHC molecule – antigen complex displayed ---cytokines released
--- cell lysis
34. Which cell type interacts with both the humoral and cell-mediated immune pathways?
a. Plasma cells
b. Cytotoxic T cells
c. Natural killer cells
d. Helper T cells
35. What is the primary function of humoral immunity?
a. It primarily defends against fungi & protozoa
b. It is responsible for transplant tissue rejection
c. It primarily defends against bacteria & viruses that have already infected cells
d. It produces antibodies that circulate in body fluids
36. Which of the following is true of active but not passive immunity?
a. Acquisition and activation of antibodies
b. Proliferation of lymphocytes in bone marrow
c. Requires direct exposure to living or simulated pathogen
d. Transfers antibodies from the mother across the placenta
37. Which of the following could prevent the appearance of the symptoms of an allergy attack?
a. Blocking attachment of the IgE antibodies to the mast cells
b. Blocking antigenic determinants of the IgM antibodies
c. Reducing number of helper T cells in the body
d. Reducing number of cytotoxic cells
38. Which statement best describes the difference in responses of effector B cells and cytotoxic T
cells?
a. B cells confer active immunity; cytotoxic T cells confer passive immunity
b. B cells kill viruses directly; cytotoxic T cells kill virus-infected cells
c. B cells secrete antibodies against a virus; cytotoxic T cells kill virus-infected cells
d. B cells accomplish the cell-mediated response; cytotoxic T cells accomplish the humoral
response
39. When a cell releases a signal molecule into the environment and a number of cells in the
immediate vicinity respond, this type of signaling is
a. Autocrine
b. Paracrine
c. Endocrine
d. Synaptic
40. Which of the following would be inhibited by a drug that specifically blocks the addition of
phosphate groups to proteins?
a. Receptor tyrosine kinase activity
b. Adenylyl cyclase activity
c. Ligand-gated ion channel signaling
d. Phosphatase activity
41. The termination phase of cell signaling requires which of the following?
a. Removal of the receptor
b. Activation of a different set of relay molecules
c. Apoptosis
d. Reversing the binding of signal molecule to the receptor
42. The activation of receptor tyrosine kinases is characterized by
a. Dimerization and phosphorylation
b. IP3 binding
c. Phosphorylation cascade
d. GTP hydrolysis
43. A cell that contains proteins enabling a hormone to selectively bind to its plasma membrane is
called a
a. Secretory cell
b. Plasma cell
c. Endocrine cell
d. Target cell
44. Which of the following statements about hormones is incorrect?
a. They are secreted into extracellular fluid
b. They circulate in the blood
c. They communicate messages throughout the body
d. They travel through a dedicated pathway
45. The hypothalamus controls the anterior pituitary by means of
a. Releasing hormones
b. Second messengers
c. Antibodies
d. Cytokines
46. If a person drinks a large amount of water in a short period of time, he or she may die of water
toxicity. ADH can help prevent water retention through interaction with target cells in the
a. Anterior pituitary
b. Kidney
c. Bladder
d. Posterior pituitary
47. Which combination of hormones helps a mother to produce milk and nurse her baby?
a. Prolactin & calcitonin
b. Oxytocin & prolactin
c. FSH & LH
d. LH & oxytocin
48. Which of the following statements about the hypothalamus is incorrect?
a. It functions as an endocrine gland
b. It is part of the CNS
c. It is subject to feedback inhibition by certain hormones
d. It secretes tropic hormones that act directly on the gonads
49. The main target organs for tropic hormones are
a. Muscles
b. Blood vessels
c. Endocrine glands
d. Kidneys
50. Consider this pathway: epinephrine – G protein coupled receptor – G protein – adenylyl cyclase
–cAMP. Identify the secondary messenger
a. cAMP
b. G protein
c. GTP
d. Adenylyl cyclase