Biology 115: Final Examination
9 May 200
Answer Key

Multiple choice: 20 points.

Forty questions worth 0.5 points each
 
1.D 2.C 3.D 4.B 5.A
6.B 7.C 8.C 9.C 10.C
11.A 12.C 13.C 14.D 15.C
16.D 17.A 18.A 19.B 20.C
21.B 22.A 23.C 24.B 25.C
26.B 27.D 28.D 29.A 30.B
31.C 32.A 33.D 34.D 35.A
36.D 37.B 38.E 39.A 40.B

Definitions: 4 points.

Eight one-sentence definitions for 0.5 points each.
41. Flagella: slender, long extensions that propel cells through fluid media.
(0.2 points for recognizing that they are cellular components; 0.3 for knowing that they provide for movement of the cell).

42. fontanels: membraneous regions located between the cranial bones in the skull of a fetus or infant. These close up as the infant matures. (second sentence not necessary for full credit; 0.3 points for knowing that they are spaces between the cranial bones; 0.1 for stating that they are present in fetuses or infants; 0.1 for knowing that they're membraneous).

43. eustachian tubes: passages that connect the nasopharynx to the middle ear, enabling equalization of air pressure; also called auditory tubes. (full credit if "mouth" is substituted for "nasopharynx". 0.4 points for recognizing that it's a passage between the mouth or nasopharynx and the ear; 0.1 for knowing that it enables equalization of air pressure. If "ear" is substituted for "middle ear", deduct 0.1 point).

44. node of Ranvier:  constriction or gap in the myelin sheath around a nerve fiber or neuron. (0.3 points for saying that it's a constriction or a gap in the myelin sheath; 0.2 points for knowing that that gap is around a nerve fiber or a neuron).

45. estrogen: a female sex hormone which, along with progesterone, maintains the primary sex organs and stimulates development of female secondary sex characteristics. (0.3 points for recognizing that it's a female sex hormone; 0.2 for saying something useful about what it does).

46. eukaryote: an organism composed of cells that contain true nuclei. (0.2 for knowing that eukaryotes are a type of organism; 0.3 for recognizing that the defining characteristic of eukaryotes is that their cells have nuclei).

47. karyotype: arrangement of all the chromosomes within a cell by pairs in a fixed order.
(0.3 for knowing that it's an arrangement of chromosomes; 0.1 for knowing that they're arranged in pairs; 0.1 for knowing that they're arranged in a fixed order).

48. succession:  sequential change in the relative dominance of species within a community. (0.4 points for knowing that it involves changes in the populations of various species in a community; final 0.1 point for using the phrase "relative dominance" or something equivalent).

Reverse Definitions: 8 points.

Sixteen reverse definitions for 0.5 points each.
  • 49. nucleolus.
  • 50. free radical.
  • 51. pulmonary fibrosis. (0.3 for "fibrosis").
  • 52. atherosclerosis.
  • 53. edema (0.3 for "inflammation").
  • 54. origin.
  • 55. cornea.
  • 56. rhodopsin.
  • 57. aldosterone.
  • 58. endometrium.
  • 59.  induction.
  • 60. plasmid.
  • 61. carcinogen.
  • 62. fossil.
  • 63. monoculture (or monoculture agriculture).
  • 64. desertification.

    • Fill in the Blanks: 5 points.

    Fill-in-the-blanks for 0.5 points each. Make sure you fill in all the blanks on each question.
  • 65. pulmonary; systemic. (in that order; 0.2 for getting "pulmonary" right; 0.3 for "systemic").
  • 66. T lymphocytes. (0.2 points for "lymphocytes").
  • 67. bacteria; viruses (0.3 for "bacteria"; 0.2 for "viruses").
  • 68. hydrogen; carbon dioxide (0.2 for "hydrogen"; 0.3 for "carbon dioxide").
  • 69. urine.
  • 70. vitamin D.
  • 71. ADP (or adenosine diphosphate); ATP (or adenosine triphosphate).

    • (in that order; 0.3 for "ADP"; 0.2 for "ATP").
  • 72. myelin; myelinated. (0.3 for "myelin"; 0.2 for "myelinated").
  • 73. cold sores and fever blisters; genital herpes

    • (0.2 for either "cold sores", "fever blisters", or both for the first part; 0.3 for "genital herpes" for the second part).
  • 74. chromatids (or sister chromatids); centromere

    • (0.3 for chromatids or sister chromatids; 0.2 for centromere).

    Diagrams: 5 points.

    Five diagrams for one point each.
  • 75. oligosaccharide; two. (0.5 points for each half)
  • 76. Most diet sodas contain aspartame, which includes a phenylalanine residue; phenylketonurics lack one of the enzymes involved in breaking down phenylalanine, resulting in a buildup of phenylketone, which is toxic. (0.2 for knowing or implying that diet sodas often contain aspartame; 0.2 for recognizing that phenylalanine is a constituent part of the aspartame molecule; 0.3 for knowing that phenylketonurics lack one of the enzymes involved in digesting phenylalanine;  0.2 for knowing that a toxic product is produced by the missing enzyme; 0.1 for knowing that phenylketone is the toxic product).
  • 77. (0.2 points for each):
  • 1. pulmonary capillaries.
  • 2. pulmonary vein
  • 3. pulmonary artery.
  • 4. vena cava (student can be more specific but doesn't have to be).
  • 5. aorta.
  • 78.the left column should be labeled "sympathetic" and the right column should be labeled "parasympathetic".
  • 79. (from bottom to top): T; C; A; G. A-T pairs involve two hydrogen bonds; G-C pairs involve three hydrogen bonds.

    • (0.1 for each of the bases. 0.3 for the fact that A-T pairs involve two hydrogen bonds; 0.3 for G-C pairs having three).

    Short answers: 5 points.

    Five short-answer questions for one point each.
  • 80. 18 (give 0.4 points for "17", even though it's wrong).
  • 81. The cilia in the nose filter the air, and the nasal passages warm and moisten it.

    • (0.4 for the filtration; 0.3 for warming; 0.3 for moistening).
  • 82. 203 = 8000. (8000 is a sufficient answer).
  • 83. Digestive proteases are prone to autolysis, which means they break themselves down; that is, one molecule of the protease can break down another one. By synthesizing them as zymogens, the organism reduces the rate of autolysis at the point of synthesis so that more of the enzyme is available when it actually needs to be used.

    • (be lenient; the concept of self-digestion is the crucial one here).
  • 84. If sperm from one species approaches an egg from another species, it will be unable to penetrate the egg's jelly coat. As a result, cross-species interbreeding is unlikely. This helps maintain species differences.

    • Full-paragraph Answers: 6 points.

    Answer three of these five for two points each.
    85. The nephrons and the ureters, which connect the kidneys to the bladder, are narrow and cannot empty very quickly. Consequently once the bladder is emptied, it takes several minutes for the urine that has backed up into the kidneys themselves to drain into the bladder. Once the the bladder refills, the urge to urinate returns.

    86. Smoking causes:
    (a) increased incidence of lung cancer due to buildup of carcinogens and cancer promoters in the lung.
    (b) increased risk for other forms of cancer, including cancer of the mouth, larynx, and esophagus.
    (c) increased risk for heart disease.
    (d) increased risk for emphysema and other non-tumor-related lung conditions.
    (e) increased risk for stroke.
    (f) supra-additive effects from other pulmonary insults like asbestos and ionizing radiation.
    (g) increased risks to those surrounding the smoker due to inhalation of sidestream smoke.

    87. Slow-twitch fibers have a steadier tug and more endurance than fast-twitch fibers. They derive their energy primarily from oxidative phosphorylation, and are well-supplied with mitochondria full of myoglobin, the oxygen-storage protein. Since myoglobin is red, these fibers are red. They are best-suited to endurance activities like long-distance running, biking, jogging, and swimming. They have a low maximum tension that develops slowly, but they are resistant to fatigue.
     Fast-twitch fibers tend to be anaerobic, relying on lactic-acid metabolism as an ATP source. Because they are less thoroughly supplied with mitochondria containing red myoglobin, they are generally white in color. They provide explosions of energy and are most helpful in sports like sprinting, weight-lifting, swinging a golf club, or putting a shot. They can develop maximum tension more rapidly and their maximum tension is greater; but they fatigue more quickly because they rely on lactate metabolism.
    88. The diagram should indicate something of the following. A cleaner version of this picture is on p.306 of Mader. 

      Pancreas secretes ---> insulin ---->  liver stores glucose as glycogen
   insulin                      \---->  muscle cells store glycogen
       ^                         \        and build protein
       |                          \-->  adipose tissue uses glucose
    after eating                          to form fat
       |                                        /
       \                                       /
        (high blood glucose)                  /
                [ Homeostasis: blood glucose ~ 75-110 mg/dL ]
                 /            ^               (low blood glucose)
                /            /*\                     \
               /            /___\                    |
      liver breaks down                            in between eating
      glycogen to glucose <--                        |
                             \                       |
      adipose tissue          \                      v
        breaks down fat <----  glucagon <------  pancreas
    89. Gene mutation may have occurred in a specific area of the world where the ethnic group lived, and there may have been little genetic exchange with outside groups. There also may have been some survival advantage to possessing the mutation in the group's original habitat.