Tutor-marked Assignment #3: Version B
This version is to be done by students whose last names begin with the letters N-Z. Answer the following questions, and submit your answers to your tutor for evaluation. Attach a “Tutor-marked Assignment” form and this page to the front of your answers. The numbers associated with the questions refer to the maximum marks allotted. Adjust the length of your answers accordingly. This assignment is worth a maximum of 20% of the course mark. Total = _____/140
A. Multiple-choice Questions
Select the single best answer for each of the following questions. Record the question numbers and your answers on a sheet of paper, or send in the questions with your answers circled. Subtotal = _____/30 1. Smooth muscle
a. is involuntary. b. is composed of nucleated cells. c. has the most rapid speed of contraction. d. is least able to remain contracted.
2. Osteocytes are found in
a. skeletal muscle. b. cartilage. c. bone. d. dense connective tissue.
3. The first event to occur during muscle fibre contraction is
a. depolarization of the muscle fibre membrane. b. release of calcium from the sarcoplasmic reticulum. c. removal of tropomyosin from actin. d. formation of cross bridges.
In the muscle cell, ATP
a. hydrolysis provides energy to flex and break the cross bridges between myosin and actin filaments. b. is produced by the breakdown of creatine and phosphocreatine. c. is needed for the release of calcium from the sarcoplasmic reticulum. d. is produced primarily by aerobic respiration during heavy exercise.
5. Which of the following features is not found in organisms with an incomplete digestive system?
a. one way movement of food through the digestive tract b. one opening through which food enters and wastes are eliminated c. secretion of digestive enzymes into digestive cavity by cells d. circulation of products of digestion throughout organism's body by diffusion e. final digestion occuring in intracellularly located phagosomes
6. In humans, protein is acted on first by ______________, and carbohydrate is acted on first by ______________.
a. trypsin; maltase b. pepsin; pancreatic emylase c. exopeptidases; sucrase d. pepsin; salivary amylase
7. Obtaining the quantities of amino acids required for good health and nutrition by a person on a vegetarian diet is
a. not difficult because each plant protein has all of the essential amino acids. b. not a problem because we have large grinding teeth to break down cellulose to release the cell's contents. c. is difficult because plant foods have a lower percentage of protein than animal foods. d. is not diffucult because amino acids can be stored for long periods of time.
8. You have just consumed a hot fudge sundae. The excess glucose will be converted to glycogen in the ______________ via the process of ______________.
a. pancreas; glycogenolysis b. liver; glycogenesis c. liver; gluconeogenesis d. small intestine; glycolysis
a. are always filled with blood. b. have valves. c. have an outer layer of muscle. d. are the sites of exchange in materials.
10. The intercalated disks between cardiac muscle cells are
a. tight junctions. b. gap junctions. c. desmosomes. d. mesosomes.
11. In an immune response the molecules which bind specifically to antigens are called
a. allergens. b. histamines. c. immunoglobulins. d. interferons.
12. Which of the following pairs is mismatched?
a. macrophage; production of IgE b. mast cell; release of histamine c. T lymphocyte; suppression of production of antibody d. natural killer cell; attack of malignant cells
13. All of the following have specialized respiratory structures except
a. grasshoppers. b. birds. c. snails. d. hydras.
14. In the diagrams, the arrows represent the movement of oxygen. The number is the partial pressure of oxygen in mm Hg in the alveolar sac or in the pulmonary capillary. Which diagram represents correctly the movement of oxygen in the lungs? a. b.
15. To maintain homeostasis of body fluids, freshwater fish
a. drink copiously. b. excrete large amounts of dilute urine. c. actively transport salt out of the body. d. do all of the above.
16. A high dietary salt intake will
a. stimulate production of aldosterone. b. reduce production of ADH. c. increase production of vasopressin. d. have no effect on production of aldosterone or ADH.
17. In a vertebrate neuron the ______________ conducts impulses toward the cell body, and the ______________ conducts impulses away from the cell body.
a. axon; dendrite b. myelin; dendrite c. dendrite; axon d. axon; vesicle
18. Three presynaptic neurons, A, B and C, synpase with the same neuron, D. The table below indicates the effect on D of the stimulation of the presynaptic neurons. Stimulation of neurons A, B or C neurons A, B and C neurons A and B neurons A and C neuron B and then C Effect on neuron D no action potential generated no action potential generated no action potential generated no action potential generated action potential generated
Which of the following conclusions is true for the data above?
a. Neurotransmitter from A depolarized D's membrane. b. Neurotransmitter from B hyperpolarized D's membrane. c. Neurotransmitter from C decreases the threshold level of D. d. The four neurons form a reverberating circuit.
19. The vital centers regulating respiration, heart beat and blood pressure are located in the
a. cerebral cortex. b. medulla. c. hypothalamus. d. red nucleus.
20. Stimulation of the brain in the occipital lobe would affect
a. hearing. b. vision. c. ability to perceive sensations such as heat, cold, touch. d. ability to control skeletal muscles.
21. Sense organs that detect changes in the pH or chemical composition of the blood are
a. mechanoreceptors. b. thermoreceptors. c. chemoreceptors. d. electroreceptors.
22. When a sensory receptor is stimulated
a. an action potential is generated. b. a receptor potential develops. c. the electrical potential difference across the membrane becomes more negative. d. the membrane becomes hyperpolarized.
23. A man with a hypofunctioning posterior pituitary would probably exhibit
a. increased urine output. b. decreased metabolic rate. c. regression of secondary sex characteristics. d. decrease in glucose uptake.
24. Glucagon, a protein, affects liver cells but not white blood cells. The most likely reason is that white blood cells
a. do not have a cytoplasmic receptor for glucagon. b. do not produce adenyl cyclase. c. do not have a membrane receptor for glucagon. d. cannot synthesize cAMP.
25. In the male, leuteinizing hormone stimulates
a. development of the seminiferous tubules. b. the production of testosterone. c. the release of FSH\s10 from the testes. d. the release of oxytocin by the posterior pituitary.
26. In a male, in the absence of hyothalamic releasing hormone
a. the anterior pituitary releases FSH but not LH. b. the testes produce testosterone but no sperm. c. neither sperm nor testosterone is produced. d. the anterior pituitary produces LH, but the testes produce no sperm.
27. The movement of cells into organized layers is called
a. determination. b. gastrulation. c. neurulation. d. epigenesis.
28. During cleavage
a. the number of chromosomes per cell increases. b. each cell increases in size. c. the amount of cytoplasm per cell decreases. d. the sperm nucleus fuses with the egg cell nucleus.
29. Learning that occurs only during a limited time in the life of the animal is called
a. habituation. b. imprinting. c. associative learning. d. insight learning.
a. is exclusively an innate behaviour. b. reflects an interaction between the genes an organism has inherited and learning. c. can occur at any time during an organism's life time. d. occurs only between mother and offspring.
B. Definition-comparison Questions
In your own words, define the following pairs of terms. In your answers, state the differences and similarities between the terms in each pair. Use complete sentences, and give specific examples where appropriate. Subtotal = _____/40 1. osteoclasts /4 cell mediated immunity /4 peritoneum /4 plasm /4 hydrostatic skeleton /4 pleura /4 somatic nervous system /4 camera eye /4 sign stimulus /4 osteocytes
antibody mediated immunity
autonomic nervous system
fixed action pattern
10. antigen /4
C. Short-answer Questions
Answer each of the following questions in complete sentences. Subtotal = _____/70 1. Describe the fate of ingested glucose in the body. /8 If muscle cells are functionally organized into motor units, then how is it possible to make graded movements (e.g., lifting two, four or six kilograms with one hand, or threading a needle)? Explain. /8 In which of the three kinds of symbiotic relationships (parasitism, mutualism and commensalism) would you expect to see the greatest specialization of adaptations between the two organisms? /4
What role does the liver play in the metabolism of amino acids and fats, and in the regulation of blood glucose? /8 If the coronary arteries become blocked, the heart stops beating and the person dies. Explain why this happens, given the amount of blood pumped through the heart with each beat. /6 If antibodies are structurally and functionally similar, explain how they are able to form complexes with many different kinds of antigens. /6 What type of compromise had to be worked out in the evolution of respiratory structures in terrestrial organisms? What two contradictory needs had to be met? /4 Insects and mammals are terrestrial animals, yet each has a different solution for the problems of excretion and osmoregulation. Why? /6 What effect would destruction of myelin have on neuronal functioning? /8
10. Why do animals “bother” to break down ingested materials into small molecules? Why not leave them as large molecules and incorporate them into their cells more efficiently? /6 11. Why do terrestrial vertebrate embryos develop an amnion? What are its functions? /6