Multiple Choice
Identify the letter of the choice that
best completes the statement or answers the question.
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1.
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Which
of the following are shown in a karyotype? a. | homologous chromosomes | b. | sex chromosomes | c. | autosomes | d. | all of the above | | |
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2.
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In
humans, a male has a. | one X chromosome only. | b. | two X chromosomes. | c. | one X chromosome and one Y
chromosome. | d. | two Y
chromosomes. | | |
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3.
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What
is the ultimate source of genetic variability? a. | inbreeding | b. | radiation | c. | hybridization | d. | mutations | | |
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4.
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Which
of the following can be observed in a karyotype? a. | a change in a DNA base | b. | an extra chromosome | c. | genes | d. | alleles | | |
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5.
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Genetic engineering involves a. | reading a DNA sequence. | b. | editing a DNA sequence. | c. | reinserting DNA into living
organisms. | d. | all of the
above | | |
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6.
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Sickle
cell disease is caused by a a. | small change in the DNA of a single
gene. | b. | change in the
size of a chromosome. | c. | change in two genes. | d. | change in the number of chromosomes in a
cell. | | |
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7.
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Which
of the following statements is true? a. | Females cannot have hemophilia. | b. | The father of a colorblind boy may be
colorblind. | c. | A sex-linked
allele cannot be dominant. | d. | The mother of a colorblind boy must be
colorblind. | | |
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8.
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The
process of DNA fingerprinting is based on the fact that a. | the most important genes are different among most
people. | b. | no two people,
except identical twins, have exactly the same DNA. | c. | most genes are dominant. | d. | most people have DNA that contains
repeats. | | |
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9.
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Selective breeding produces a. | more offspring. | b. | fewer offspring. | c. | desired traits in offspring. | d. | transgenic organisms. | | |
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10.
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The
purpose of gene therapy is to a. | cure genetic disorders. | b. | determine the sequences of
genes. | c. | remove mutations
from genes. | d. | change dominant
alleles to recessive alleles. | | |
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11.
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Because the allele that causes a form of leukemia and the allele that causes
neurofibromatosis are located on chromosome 22, they a. | are dominant. | b. | are never separated by
recombination. | c. | are
linked. | d. | contain
repetitive DNA. | | |
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12.
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What
is the approximate probability that a human offspring will be female?
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13.
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The
failure of chromosomes to separate during meiosis is called a. | nondisjunction. | b. | X-chromosome inactivation. | c. | Turner’s syndrome. | d. | Down syndrome. | | |
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14.
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Which
of the following is determined by multiple alleles? a. | Rh blood group | b. | ABO blood group | c. | PKU | d. | Huntington’s disease | | |
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15.
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Which
of the following have been produced by selective breeding? a. | horse breeds | b. | cat breeds | c. | dog breeds | d. | all of the above | | |
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16.
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What
is the probability that a human sperm cell will carry an X chromosome?
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17.
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Which
of the following is most likely to bring together two recessive alleles for a genetic
defect? a. | inbreeding | b. | hybridization | c. | genetic engineering | d. | transformation | | |
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18.
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Sex-linked genes are located on a. | the autosomes. | b. | the X chromosome only. | c. | the Y chromosome only. | d. | both the X chromosome and Y
chromosome. | | |
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19.
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How
many chromosomes are shown in a normal human karyotype?
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20.
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Why is
Dolly a clone? a. | The source of her
DNA was a single body cell. | b. | The DNA molecules in all her cells are
identical. | c. | She was produced
using the DNA from an adult’s egg cell. | d. | She is genetically identical to her
offspring. | | |
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21.
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The
Human Genome Project is an attempt to a. | make a DNA fingerprint of every person’s
DNA. | b. | sequence all
human DNA. | c. | cure human
diseases. | d. | identify alleles
in human DNA that are recessive. | | |
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22.
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Colorblindness is more common in males than in females because a. | fathers pass the allele for colorblindness to their sons
only. | b. | the allele for
colorblindness is located on the Y chromosome. | c. | the allele for colorblindness is recessive and located on
the X chromosome. | d. | males who are colorblind have two copies of the allele for
colorblindness. | | |
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23.
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A cat
that has only orange spots a. | has no Barr bodies. | b. | must be a male. | c. | must be a female. | d. | may be a male or a female. | | |
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24.
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What
has been an advantage of producing transgenic plants? a. | increasing the food supply | b. | using more pesticides | c. | producing clones | d. | studying human genes | | |
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25.
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Human
females produce egg cells that have a. | one X chromosome. | b. | two X chromosomes. | c. | one X or one Y chromosome. | d. | one X and one Y chromosome. | | |
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