True/False
Indicate whether the statement is true or
false.
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1.
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If you cross two hybrids its possible to get a purebred for a particular
trait.
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2.
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Chromosomes are the carriers of genes from parents to offspring.
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3.
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Alleles are different forms of a gene.
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4.
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Marfan syndrome is a genetic disorder.
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Multiple Choice
Identify the choice that best completes the
statement or answers the question.
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5.
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What is probability?
a. | the actual results from a series of events | b. | a number that
describes how likely it is that an event will occur | c. | the number of times a coin lands heads
up |
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6.
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What is the probability of producing a tall pea plant from a
genetic cross between two hybrid tall pea plants? hint :draw a punnet square.
a. | one in four | b. | four in four | c. | three in
four |
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7.
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What does a Punnett square show?
a. | only the recessive alleles in a genetic cross | b. | only the dominant
alleles in a genetic cross | c. | all the possible outcomes of a genetic
cross |
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8.
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If a homozygous black guinea pig (BB) is crossed with a
homozygous white guinea pig (bb), what is the probability that an offspring will have
black fur?
a. | 50 percent | b. | 75 percent | c. | 100
percent |
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9.
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An organism’s physical appearance is its
a. | phenotype. | b. | codominance. | c. | heterozygous. |
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10.
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An organism’s genotype is its
a. | feather color. | b. | physical appearance. | c. | genetic
makeup. |
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11.
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An organism that has two identical alleles for a trait is
a. | heterozygous. | b. | tall. | c. | homozygous. |
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12.
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A heterozygous organism has
a. | two different alleles for a trait. | b. | only one allele for a
trait. | c. | two identical alleles for a trait. |
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13.
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Which term refers to physical characteristics that are studied in
genetics?
a. | traits | b. | generations | c. | offspring |
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14.
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Factors that control traits are called
a. | recessives. | b. | parents. | c. | genes. |
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15.
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The different forms of a gene are called
a. | masks. | b. | factors. | c. | alleles. |
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16.
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According to the diagram below, which trait is controlled by a dominant
allele?
 a. | white flowers | c. | green seeds | b. | purple flowers |
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17.
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According to the diagram below, in which generation are the parents
purebreds?
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18.
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According to the diagram below, which generation are the parents
hybrids?
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19.
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According to the diagram below, In the F2 generation, what
percentage of offspring have purple flowers?
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20.
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The geologic time scale is a record of
a. | the thickness of sedimentary rock layers. | b. | the rate of fossil
formation. | c. | the life forms and geologic events in Earth’s history. | d. | the time since the
evolution of dinosaurs. |
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21.
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How did Earth’s atmosphere change about 2.5 billion years ago when
plants began using photosynthesis to make food?
a. | The amount of oxygen in the atmosphere increased. | b. | Mass extinctions
occurred. | c. | The oceans became larger. | d. | Rainfall
increased. |
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22.
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About 260 million years ago, Earth’s continents moved together to form the
supercontinent called
a. | Antarctica. | b. | Cambria. | c. | North
America. | d. | Pangaea. |
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23.
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During the Cambrian Explosion that began the Paleozoic Era, the many new
forms of life that evolved
a. | lived on land. | b. | were invertebrates that lived in the
sea. | c. | were vertebrates covered with scales or fur. | d. | were
single-celled. |
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24.
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During the Devonian Period, animals that could live on land and the
water were
a. | trilobites | b. | reptiles | c. | amphibians | d. | dinosaurs |
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25.
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What do most scientists think caused the mass extinction of dinosaurs at
the end of the Cretaceous Period?
a. | Volcanic eruptions covered large areas with lava. | b. | An asteroid from
space struck Earth. | c. | An ice age covered most of Earth with
ice. | d. | The dinosaurs ate too many other organisms and then
starved. |
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