Zoo 317: Heredity, Evolution and Society
Fall 1998
Exam I from Fall 1997
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This exam, administered in Fall 1997, covered the same material as the first exam to be given in Fall 1998. None of the questions that appear below will appear on the 1998 exam. However, If you can answer all the questions on the 1997 exam, you should do very well on the 1998 exam.
Reminder: Bring a to class. You will need it to turn in your exam. |
Mark the correct answer on the separate answer sheet with a #2 pencil. On the answer sheet, be sure to (1) print your name, (2) code your name, (3) enter your SSN, (4) code your SSN, (5) sign with your usual signature. There is one best answer for each question. Other answers may be partially correct but not in all circumstances. If you must erase, do so thoroughly so that the machine will not mistake your intentions. Answer sheets must be turned in no later than 9:50. You may keep the exam. The answer key will be posted outside the exam room about 9:25.
1. According to the theory of pangenesis, inherited traits are influenced by
a. germ cells only.
b. germ cells and internal organs, but not muscle and skin.
c. derivatives of endoderm.
d. all tissues.
2. The basic unit of life is
a. the cytoplasm.
b. the lysosome.
c. the nucleus.
d. the cell.
3. Spontaneous generation refers to
a. the origin of living from nonliving matter.
b. the formation of new species in evolution.
c. the development of an unfertilized egg.
d. the production of energy by mitochondria.
4. Bacteria are different from eukaryotes in that they have no
a. ribosomes.
b. genes.
c. nuclei.
d. cell membranes.
5. Which of the following organelles is most important in the ability of a cell to use oxygen to produce energy?
a. Centrosomes.
b. Mitochondria.
c. Lysosomes.
d. Microtubules.
6. During development from a zygote to a fetus,
a. there is selective loss of chromosomes in different tissues.
b. there is selective activation of genes in different tissues.
c. there is random loss of chromosomes.
d. new genes are produced by preprogrammed mutation.
7. Autosomes are
a. self-replicating organelles in the cytoplasm.
b. cytoplasmic organelles that function in the breakdown of various substances.
c. chromosomes that regulate their own replication.
d. chromosomes other than the sex chromosomes.
8. A standardized array of chromosomes is known as
a. a chromotype.
b. a karyotype.
c. a genotype.
d. a nucleotype.
9. A commonly used cell type for examination of human chromosomes is the
a. red blood cell.
b. corneal cell.
c. lymphocyte.
d. oocyte.
10. DNA replication occurs during the _______ phase of the cell cycle.
11. The movement of chromosomes to opposite poles during cell division is called
a. telophase.
b. anaphase.
c. prophase.
d. metaphase.
12. In metaphase, each chromosome has
a. two centromeres.
b. two chromatids.
c. two polar bodies.
d. two Barr bodies.
13. In mitosis, the daughter cells receive
a. half the number of chromosomes as the parental cell.
b. the same number of chromosomes as the parental cell.
c. twice the number of chromosomes as the parental cell.
d. only maternally imprinted chromosomes.
14. As compared to mitosis, chromosomes in meiosis
a. do not pair.
b. do not undergo crossing over.
c. go through two metaphases.
d. go through two rounds of DNA replication.
15. Crossing over involves exchange of genetic information between
a. sister chromatids.
b. nonsister chromatids.
c. homologous spermatids.
d. nonhomologous chromosomes.
16. Meiosis is different from mitosis in that meiosis
a. causes an increase in ploidy.
b. occurs only in vertebrates.
c. generates daughter cells that are genetically identical to the parent cell.
d. involves pairing of homologous chromosomes.
17. Polar bodies
a. are the points of origin of spindle fibers.
b. are the cell masses around which the gonads form.
c. are meiotic products in females.
d. form at opposite ends of the cell during cell division.
18. A fertilized egg is often called
a. an oocyte.
b. an oogonium.
c. a zygote.
d. a gamete.
19. Mendel found that in the F2 generation from a monohybrid cross,
a. all plants exhibited the dominant character.
b. some plants exhibited the dominant character and some the recessive.
c. all plants exhibited the recessive character.
d. all plants were like the F1 generation.
20. Genetic segregation refers to
a. the separation of alleles in meiosis.
b. the separation of germ cells from somatic cells in development.
c. the formation of double heterozygotes in a dihybrid cross.
d. the lack of fertility in crosses of related species.
21. Two loci assort independently. Most likely,
a. they are expressed in different tissues.
b. they are closely linked.
c. one is X-linked, the other Y-linked.
d. they are on different (nonhomologous) chromosomes.
22. An allele is described as dominant if it
a. codes for an enzyme.
b. prevents expression of other alleles.
c. is expressed in heterozygotes.
d. is expressed only when homozygous.
23. One of the principles established by Mendel was
a. mitochondrial transmission causes offspring to resemble male parents.
b. genetic contributions from the two parents are equal.
c. alleles may be present but not expressed because of imprinting or X-inactivation.
d. alleles received from the male parent are preferentially expressed.
24. A child is diagnosed as having achondroplasia, a rare form of dwarfism inherited as an autosomal dominant trait. One would expect
a. only male sibs also to be affected.
b. only maternal relatives to be affected.
c. both maternal and paternal relatives affected.
d. either the mother or father also affected.
25. In a person who is heterozygous for the A and B alleles of the ABO blood groups, both traits are expressed. With respect to each other, these alleles are
a. codominant.
b. dominant.
c. recessive.
d. epistatic.
26. A brother and sister are diagnosed as having muscular dystrophy. Neither parent is affected. The gene responsible for the muscular dystrophy in this family must be
a. autosomal dominant.
b. autosomal recessive.
c. X-linked dominant.
d. X-linked recessive.
27. Phenylketonuria (PKU) is an autosomal recessive trait in humans. Let P be the normal allele and p the PKU allele. If a child has PKU, the parental mating probably was
a. Pp × pp.
b. Pp × Pp.
c. Pp × PP.
d. pp × pp.
28. Blood group A is dominant to group O. A man with group A marries a group O woman. Their first child is group O. What is the likelihood that their next child will also be group O?
a. zero
b. 1/4
c. 1/2
d. 1
29. Huntington disease has been a problem in genetic counseling because
a. it segregates abnormally in meiosis.
b. it can be caused by mutations at many different loci.
c. homozygosity is lethal in the embryonic stage.
d. it has a late age of onset.
30. Red-green colorblindness occurs primarily in males because
a. one X chromosome is inactive in females.
b. its expression is dependent on testosterone.
c. it is due to a dominant locus on the Y chromosome.
d. it is due to a recessive locus on the X chromosome.
31. [This question included a diagram which has not been converted into a graphic suitable for the web.]
32. X-linked recessive inheritance can be ruled out for a very rare trait in a pedigree if
a. only males are affected.
b. a boy and his maternal uncle are both affected.
c. a boy and his father are both affected but no maternal relatives are affected.
d. a boy and his maternal grandfather are both affected.
33. Pseudoautosomal genes are
a. nonfunctional genes.
b. genes in the homologous regions of the X and Y chromosomes.
c. genes on an inactive autosome.
d. genes that are lost during embryonic development.
34. Which of the following statements is correct?
a. The Y chromosome has approximately the same number of genes as the X chromosome.
b. The Y chromosome has only a few genes, but they are essential for all persons.
c. The Y chromosome has only a few genes, most of which seem to be concerned with sex determination.
d. The Y chromosome has no genes as such, but has something to do with sex determination.
35. Males with one allele for hemophilia on the X chromosome typically express this disorder. This is because
a. they are hemizygous for X-linked genes.
b. the hemophilia gene is codominant.
c. the hemophilia gene is in the pseudoautosomal region of the X.
d. hemophilia is transmitted as a maternally inherited disorder.
36. A woman has red-green colorblindness, an X-linked recessive trait. Her husband has normal color vision. She is pregnant. What is the likelihood that the child will be colorblind?
37. Mitochondrial genes are characterized by
a. X-linked inheritance.
b. maternal transmission.
c. paternal transmission.
d. RNA rather than DNA.
38. Mitochondrial genes differ from nuclear genes in the following:
a. They do not have DNA.
b. They do not recombine.
c. They function only in females.
d. They are transmitted only by sperm.
39. A man with hemophilia and red-green colorblindness (both at the tip of the long arm of the X chromosome) has a normal daughter. Her sons are most likely to have
a. either condition but not both.
b. colorblindness but not hemophilia.
c. hemophilia but not colorblindness.
d. both conditions or neither.
40. A cross between two mouse strains of genotypes AABB × aabb produces F1 offspring of genotype AaBb. Which of the gametes produced by the F1 are recombinant?
a. AB, ab
b. Ab, aB
c. AB, Ab, aB, ab
d. None of the above combinations.
41. The Rh and Duffy blood groups are syntenic. Therefore,
a. they are on the same chromosome.
b. they cannot recombine.
c. they are expressed together.
d. they are alleles.
42. Two loci are 5 centimorgans apart. This means that they
a. are separated by 5 nanometers.
b. recombine 5% of the time.
c. have 5 intervening sequences between them.
d. are located in different chromosome bands.
43. A rare disease clusters in families. However, monozygotic twins are no more often both affected than are dizygotic twins. Therefore, the disease is
a. probably inherited.
b. probably environmental.
c. environmental but with inherited susceptibility.
d. probably a defect in mitochondria.
44. Studies of adopted children show that they resemble their biological parents more than their adoptive parents in the degree of obesity. Therefore,
a. obesity is entirely a matter of heredity.
b. obesity is entirely environmental, in spite of these results.
c. heredity contributes to obesity more than environment in the groups studied.
d. The adoption method is inappropriate for study of an environmental trait.
45. Monozygotic twins are more often concordant for tuberculosis than are dizygotic twins. This suggests that
a. tuberculosis is inherited.
b. only certain genotypes are susceptible to tuberculosis.
c. heredity is one of the factors that influence risk of a tuberculosis infection.
d. MZ twins are more likely to transmit the infectious agent to each other than are DZ twins.
46. Height is an example of a trait that ordinarily is
a. continuous.
b. discontinuous.
c. hydrophilic.
d. monogenic.
47. The average height of present-day Americans of European descent is greater than the height of Medieval Europeans. This means that
a. heritability of height is high.
b. heritability of height is low.
c. present-day Americans are more likely to reach their genetic potential for height.
d. This comparison provides no information on the question of heritability of height.
48. A young man had black hair but decided to dye it blond. He is now an example of
a. epistasis.
b. wild-type.
c. parthenogenesis.
d. phenocopy.
49. A gene is described as 50% penetrant. This means that
a. it is present in 50% of the population.
b. it is transmitted from an affected parent to 50% of offspring.
c. only 50% of the persons who have the gene have an altered phenotype.
d. 50% of the cases are due to environment.
50. Genetic ratios are more difficult to study in humans than in experimental organisms because
a. they are not consistent in humans.
b. different rules apply in plants and animals.
c. human chromosomes tend to get lost from hybrids.
d. human families are small.
last revision: 9 September 1998
owned by:
Dr. Eldon Sutton