1. Which one of the following is the basic unit of heredity?
a. cell b. nucleus c. chromosomes d. gene
2. The number of functional gametes derived from each primary Oocyte is (are) :
a. 1 b. 2 c. 3 d. 4
3. Cytoplasmic inheritance:
a. does not follow Menedlian laws
b. The maternal cytoplasm plays the dominant role
c. replication of mitochondria is an example
d. all of the above
e. only a and c of the above
4. The classical phenotypic Mendelian ratio for dihybrid cross is
a. 3:1 b. 1:2:1 c. 1:1 d. 9:3:3:1
5. Which one of the following will be the genotype for homozygous tall, round seed and yellow flower plant:
a. Tt Rr Yy b. tt rR yY c. TT RR YY d. TT RY RY
6. A child is blue eyed only if it has inherited one allele for
this character from each parent. Which one of the following
phenomenon will explain this type of inheritance:
a. sex-linked b. recessiveness c. incomplete dominance d. epistasis
7. The phenotypic ratio is computed on the basis of :
a. the genetic make-up of the organism
b. the outward appearance of the organism
c. both a and b above
d. parents genetic make-up
8. If the diploid number of chromosomes in an organism is 12, the organism contains_________pairs of autosomes per cell:
a. 1 b. 6 c. 5 d. 12
9. The probability that a woman with three sons will give birth
to a fourth son is:
a. 1/4 b. 1/2 c. 1/8 d. 1/6
10. A black male (AABB) marries a mulatto woman (AaBb). What is
the probability of their offspring being as dark skinned as the father?
a. 1/4 b. 1/2 c. all will be as dark skinned d. none will be as dark
11. Choose the INCORRECT statement from the following as they relate to human sex chromosomes:
a. XXX males are sterile and feminized to some extent
b. XXX females are often normal in appearance/fertility
c. XO females are always underdeveloped sexually and are
sterile
d. XY males are most of the time normal males
12. Which of the following is an example of aneuploidy:
a. 4n b. trisomy 2l c. XO d. 2n
13. Mendel succeded in discovering the principles of heredity because
a. He began with crosses of plants differing primarily in one trait.
b. He kept his record in orderly fashion.
c. He applied statistical methods to analyse his data.
d. All of the above.
14. A metacentric chromosome
a. That has lost one arm of its two arms
b. That has two arms that are alike
c. That has a centromere at the end
d. That has lost a centromere
15. The Hardy-Weinberg principle will give the best indication of gene frequency when:
a. Mating is at random in a large population
b. The rate of mutation of harmful genes is balanced by their rate of elimination by selection
c. There is no gene flow as result of immigration
d. All of the above
16. If the genotype of a trait is Gg then possible gametes are:
a. Gg b. GG and gg c. G and g d. Gg, G, g, and gg
17. Which of the following is (are) example (s) of euploidy:
a. 2n b. trisomy 2l c. XO d. both b and c
18. Mendel's first law states that:
a. Alleles of the same trait segregate during the formation of
gametes
b. Alleles of different traits separate independently of each
other in the formation of gametes.
c. Alleles of different traits moves together
d. Chromosomes of different traits move together
19. When two plants are crossed and 75% of the offsprings are tall and 25% of the offsprings are short, then the parents were:
a. TT * tt b. TY * Ty c. Tt * Tt d. TT * Tt
20. A color blind woman is married to a normal man. All the sons
will be:
a. like the father b. like the mother
c. half like father d. none of these
21. A cross between a homozygous recessive individual and a
homozygous dominant individual would produce:
a. 50% homozygous dominant and 50% homozygous recessive
b. All heterozygous
c. 75% homozygous dominant and 25% homozygous recessive
d. All homozygous dominants
22. Fertilization of an XX egg by an X sperm results in what is
now called_______. These persons may have following characters:
a. Turner syndrome; sterile, may be fertile male, offsprings with normal euploid set of chromosomes
b. Klinofelter syndrome: sterile, may be fertile female offsprings with aneuploid set chromosomes.
c. Triple X syndrome: mostly fertile, may be sterile, offspring with aneuploid set of chromosomes.
d. Tripple X syndrome: all females, mostly fertile, offsprings with euploid set of chromosomes.
23. Which one of the following is the correct formula for chi
square calculations:
a. Chi Square = (Observed - Expected)3/Expected
b. Chi Square = (Observed - Observed/Observed)
c. Chi Square = (Observed - Expected)2/Expected)
d. Chi Square = (Observed - Expected/Expected)
24. In the Watson-Crick model of a double helix, the "steps" of
the spiral staircase are composed of
a. sugars b. a purine/a pyrimidine c. purines d. pyrimidines
25. Which one of the following is not a mutagenic agent
a. Cigarette smoking b. UV light c. radon
d. X-ray e. radioactive rays f. mustard gas
g. orange juice
26. Which one of the following is not a reason why human beings
are unfavorble for studies of inheritance
a. Some human traits are determined by more than one gene
b. It is difficult to perform human genetic studies in controlled environment.
c. They provide more reliable results since there are two of
a kind
d. They provide information about environment or genetic influence on certain human traits.
27. Studies on twins are important because:
a. Single human traits are difficult to compare
b. Twins are more common as a result of increasing use of
fertility drugs.
c. They provide more reliable results since there are two of a kind
d. They provide information about environmental or genetic influence on certain human traits.
28. Hemophilia is a recessive sex-linked trait. What would be the phenotype of the progeny of the sons from a mating between a female hemophiliac and a normal male?
a. 1/2 of the sons will be hemophilic
b. 1/2 of the daughters will be hemophilic
c. all of the daughters will be hemophilic
d. all of the sons will be carriers
29. Mongolian spots is a recessive sex-linked trait. Only one
son out of six offsprings form two "normal-looking" parents
show the trait. Which one of the following is correct.
a. The mother is homozygous normal
b. The mother is homozygous carrier
c. The father's genotype cannot be determined
d. none of the above
30. For the Hardy-Weinberg Law to hold in a population, which one
of the following is not necessary?
a. large interbreeding population
b. high mutation rates
c. random mating
d. no natural selection
31. The term genotypes refers to:
a. the genetic constitution of an individual
b. the type of genes of an individual
c. the interaction between closely linked genes
d. the number of copies of genes in an individual
e. the physical appearance of an individual
32. The percentage of occurrence of a particular gene is a population is known as the gene
a. frequency b. pool c. number d. total
33. The random establishment of non-adaptive, bizarre types in
small populations is known as
a. genetic pool b. migration
c. selection pressure d. the Hardy-Weinberg Law
34. The wxpression p2+2pq+q2=1 is an algebraic statement illustrating:
a. the distribution of genotypes for a particular trait in a
large population
b. the rate of mutation
c. the relationship between isolation and variation
d. the constant change of gene frequencies in a randomly mating population
35. According to population genetics evolution is best defined as
a. any change in gene frequency
b. variation due to the environment
c. a tendency toward geographic isolation
d. the result of interbreeding
36. The frequency of a gene in a population will not be largely affected by
a. mutation b. small population size
c. selective migration d. random mating
37. Gene duplication takes place during
a. telophase b. anaphase
c. interphase d. metaphase
38. If height is controlled by polygenetic inheritance in man, which of the following people has a genetic potential which would allow them to be taller than a person with the genotype
AaBBCcDdEE?
a. AaBBCcDdEe b. AabbccDDEE
c. AABBCcDDEe d. aaBBccDDee
39. Human body cells usually have 46 chromosomes during anaphase stage of mitosis, a cell will have
a. 92 chromosomes b. 46 chromosomes
c. 123 chromosomes d. 44 chromosomes
40. In peas, yellow color is dominant to green. If a homozygous
yellow plant is crossed with a green plant, then the expected
phenotypic ratios of the offsprings would be:
a. 3/4 yellow: 1/4 green b. all green
c. 3/4 green: 1/4 yellow c. all yellow
41. Usually a recessive sex-linked trait will be expressed more often
a. in males than in females b. in females than in males
c. to the same extent both in males and in females
d. will only be expressed in males
42. Select the incorrect association
a. Down Syndrome ---------Trisomy 21
b. Edward Syndrome ------- Trisomy 22
c. Klinefelter Syndrome ----XXY
d. Turners Syndrome --------45X
43. Individuals who are taller than usual are associated with the condition
a. XO b. XXX c. XXY d. XYY
44. Each is a characteristic of the Turner Syndrome except:
a. congential heart defect
b. biologically males
c. gonads non-functional
d. reduced skill in spatial relationships
45. Fertilization of an ovum produced by nondisjunction can produced a zygote will all chromosomal combinations except
a. XO b. XXX c. XXY d. XY
46. The human Y chromosome
a. can produce malenes in a XXperson
b. contains many gene loci
c. contributes mainly to femaleness
d. has a slight effect on sex determination
47. DNA probes can be used to locate a gene on a chromosome by its
a. affinity of RNA c. large size
b. complimentary d. protein composition
48. In a pedigree chart, a child is afflicited with a disease caused by a recessive allele. One of his parents is homozygous recessive. The other normal parent must be:
a. AA b. Aa c. AO d. aa
49. Human pattern baldness is best described as
a. autosomal dominant c. sex-linked
b. autosomal recessive d. sex-influenced
50. When a pure line sweet peas with red flowers are crossed
with pure line plants having white flowers, all the F1
plants have pink flowers. The F2 generation will be as
a. 2RR : 1RW :1WW c. 2RR : 2WW
b. 1RR : 2RW : 1WW d. 1RR : 2RW : 2WW
51. Mr. Doe is type O blood and his wife is type AB. Which
one of these blood grups will their offsprings have
a. IBIB and IAIB b. IAi and IBIA
c. IAi : IBi d. AB : O
52. If a girl is hemophilic chances phenotype of the parents
are as follows:
a. the mother must be hemophiliac
b. the mother must be a carrier
c. the father must be hemophiliac
d. the father must be a carrier
53. Each is a component of DNA nucleotide sugar except:
a. deoxyribose b. Nitrogen base
c. phosphate group d. ribose sugar
54. Messenger RNA
a. carries genetic instruction from DNA
b. duplicates the job of ribosomal RNA
c. is made at the ribosome
d. transports amino acids for protein synthesis
55. In humans, multiple modifying genes have a large influence
on:
a. Blood type b. eye-color
c. hair texture d. weight
56. The techniques which have been developed and by which the
genotype of an organism can instead be modified in a directed
and predetermined way may be known as
a. Recombinant DNA technology only
b. genetic-engineering
c. gene cloning
d. all of the above
e. none of the above
57. Which is not a pyrimidine of the nucleic acids?
a. guanine b. thymine c. cytosine d. uracil
58. DNA always differs from RNA by:
a. forming hydrogen bonds between strands
b. having thymine and not uracil
c. being found only in the nucleus
d. having a sugar-phosphate backbone
59. Which of the following statemens about genetic counseling are
true?
a. A counselor can predict whether or not a child will have a
genetic disorder
b. A genetic counselor needs a detailed history called a
pedigree chart.
c. The decision to have or not to have a child is solely up to the parents.
d. The counselor should share his or her value system with the parents
e. b and c only
60. The classical phenotypic ratio for a monohybrid test cross is
a. 3:1 b. 1:2:1 c. 1:1 d. 9:3:3:1
61. The ultimate source of all new genes in a population is due to
a. mitosis b. mating c. meiosis d. mutation
62. All of the following are conditions under which evolution would not occur except:
a. large population b. non-random reproduction
c. no mutations d. no immigration or emigration
63. Genetic drift may lead to evolution in populations that are:
a. any size b. large c. small d. all of the above
64. Populations that are separated by geographic barriers will tend to differ because
a. gene frequencies usually differ between them
b. mutations vary between populations
c. there are different environmental pressures
d. all of the above
65. One of these statements is incorrect with regard to allele
frequencies.
a. gene frequencies usually differ between them
b. mutations vary between populations
c. there are different environmental pressures
d. all of the above
66. Which of the following statements about genetic counseling are true?
a. A counselor can predict whether or not a child will have a
genetic disorder.
b. A genetic counselor needs a detailed history called a pedigree chart.
c. The decision to have or not to have a child is solely up
to the parents.
d. The counselor should share his or her value system with the parents.
67. These scientists have been given the credit as the authors for the foundation of Population genetics.
a. Copernicus and Galileo b. Hardy and Weinberg
c. Aristotle and Plato d. Einstein and Weinberg
68. Hardy--Weinberg theory can be called all except
a. Principle b. Law c. Matriculation d. Equation
69. A man an A group blood marries a wife an AB blood type.
What are the possible blood types of their children?
a. A b.AB c. B d. all of the preceding
70. A sick person an AB blood type needs blood transfusion.
Which blood type of person can give blood to him?
a. AB b. A c. O d. B e. all of the preceding
71. Suppose the only alleles determine blood type are A and B,
and that they are co-dominant of parents, both which type AB,
have children, what are the ratio of the children expected
blood type? Genotype of each type
a. 1 type A, 2 type AB: 1 type B
b. 1 type A: 1 type B
c. 3 type AB, 1 type A : 1 type B
d. all type AB
72. Select the incorrect statement about the number and type of
chromosomes in the normal human male:
a. there are 44 autosomal chromosomes
b. there are 46 chromosomes total
c. there are two x chromosomes
d. there is one Y chromosome
73. In the typical somatic cell, the number of chromosomes is symbolized as
a. 1n b. 2n c. 3n d. 4n
74. Select the incorrect statement:
a. a recessive allele is only expressed when it is homozygous
b. a dominant allele can be expressed when heterozygous
c. a codominant allele may express itself completely or partically when homozygous or heterozygous respectively
d. dominant alleles may not be expressed
75. Cytoplasmic inheritance:
a. does not follow Mendelian Laws
b. the maternal cytoplasm plays the dominant role
c. replication of the mitochondria is an example
d. all of the above
76. Which statement is incorrect concerning x and y chromosomes?
a. x is larger than y
b. they are not homologous
c. xy is a genotypic male
d. traits appearing on x but not y are called sex-linked
77. Homozygous refers to
a. similar types of chromosomes
b. having similar functions on an evolutionary basis
c. particles in a solution not being separable microscopically
d. idnetical alleles for a given trait
78. Which of the following is an example of aneuploidy?
a. 4n b. trisomy 21 c. xo (no y chromosome)
d. both b and c
79. Inversion:
a. when the sequence of genes on the chromosome is reversed
b. when a part of one chromosome attaches to another
c. a part of the chromosome is missing
d. when a part of the chromosome is repeated
80. Gene translocation:
a. when a part of the chromosome is duplicated
b. when a part of the chromosome is missing
c. when the sequence of genes on the chromosome is reversed
d. situation when a part of one chromosome attaches to another
81. Gene deletion
a. when the sequence of genes on the chromosome is reversed
b. when a part of the chromosome is repeated
c. when a part of the chromosome is missing
d. when a part of the chromosome attaches to another
82. Gene duplication
a. when the sequence of genes on the chromosome is reversed
b. when a part of one chromosome is attached to another
c. when a part of the chromosome is repeated
d. when one chromosome lives and dies
83. Select the incorrect statement about the number and type of
chromosomes in the normal human male:
a. there are 44 autosomal chromosomes
b. there are 46 chromosomes total
c. there are two x chromosomes
d. there is one y chromosome
84. If the genotype for a trait is xy, which are the possible gametes
a. x only b. xy c. y only d. x and y
85. Cross AB/ab x ab/ab Possible gametes:
a. AB;Aa b. AB;ab c. aA;ab d. ab;Ab
86. Genotypic ratio:
a. 2:1:;1 b. 1:2:1 c. 1:1:1 d. 1:1:2
87. Phenotypic ratio:
a. 3:1 b. 1:3 c. 1:1 d. 1:4
88. Gene linkage:
a. decreases the number of possible phenotypes
b. affects the ratio of phenotypes
c. causes a deviation from classical Mendelian genetics
d. involves all the preceding
89. Which of the following organelles posses their own DNA
a. centriole b. endoplasmic reticulum
c. mitochondria d. cell membrane
90. Cytoplasmic inheritance
a. does not follow Mendelin laws
b. the maternal cytoplasm plays the dominant role
c. replication of mitochondria is an example
d. all of the above e. only a and c
91. How many chromosomes does a mule has whose mother, a horse
and 64 and whose father, an ass, had 62?
a. 60 b. 62 c. 63 d. 65
92. In Andalusian chicken, the offsprings of homozygous black
feathered and homozygous white-feathered parents are blue feathered. Which one of the following phenomena will explain this type of inheritance
a. sex linked b. recessiveness
c. incomplete dominance d. dominance