Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
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1. |
The “father” of genetics was
a.
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T. A. Knight.
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c.
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Gregor Mendel.
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b.
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Hans Krebs.
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d.
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None of the above
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2. |
Mendel obtained his P generation by allowing the plants to
a.
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self-pollinate.
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c.
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assort independently.
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b.
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cross-pollinate.
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d.
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segregate.
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3. |
What is the probability that the offspring of a homozygous dominant individual and a homozygous recessive individual will exhibit the dominant phenotype?
a.
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0.25
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c.
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0.66
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b.
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0.5
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d.
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1.0
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4. |
True-breeding pea plants always
a.
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are pollinated by hand.
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b.
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produce offspring with either form of a trait.
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c.
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produce offspring with only one form of a trait.
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d.
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are heterozygous.
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5. |
The first filial (F1) generation is the result of
a.
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cross-pollination among parents and the next generation.
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b.
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crosses between individuals of the parental generation.
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c.
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crosses between the offspring of a parental cross.
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d.
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self-fertilization between parental stock.
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6. |
Which of the following is the designation for Mendel’s original pure strains of plants?
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7. |
A genetic trait that appears in every generation of offspring is called
a.
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dominant.
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c.
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recessive.
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b.
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phenotypic.
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d.
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superior.
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8. |
To describe how traits can disappear and reappear in a certain pattern from generation to generation, Mendel proposed
a.
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the law of independent assortment.
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b.
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the law of segregation.
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c.
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the law of genotypes.
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d.
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that the F2 generation will only produce purple flowers.
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9. |
When Mendel crossed pea plants with two contrasting traits, such as flower color and plant height,
a.
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these experiments led to his law of segregation.
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b.
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he found that the inheritance of one trait did not influence the inheritance of the other trait.
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c.
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he found that the inheritance of one trait influenced the inheritance of the other trait.
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d.
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these experiments were considered failures because the importance of his work was not recognized.
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10. |
If an individual has two recessive alleles for the same trait, the individual is said to be
a.
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homozygous for the trait.
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c.
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heterozygous for the trait.
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b.
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haploid for the trait.
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d.
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mutated.
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11. |
An individual heterozygous for a trait and an individual homozygous recessive for the trait are crossed and produce many offspring that are
a.
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all the same genotype.
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c.
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of three different phenotypes.
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b.
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of two different phenotypes.
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d.
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all the same phenotype.
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In humans, having freckles (F) is dominant to not having freckles (f). The inheritance of these traits can be studied using a Punnett square similar to the one shown below.
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12. |
Refer to the illustration above. The genotype represented in box “1” in the Punnett square would
a.
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be homozygous for freckles.
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b.
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have an extra freckles chromosome.
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c.
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be heterozygous for freckles.
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d.
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have freckles chromosomes.
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13. |
Refer to the illustration above. The genotype in box “3” of the Punnett square is
a.
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FF.
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c.
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ff.
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b.
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Ff.
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d.
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None of the above
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14. |
How many different phenotypes can be produced by a pair of codominant alleles?
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15. |
Refer to the illustration above. The phenotype represented by the cell labeled “1” is
a.
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green, inflated.
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c.
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yellow, inflated.
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b.
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green, constricted.
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d.
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yellow, constricted.
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16. |
2,000 yellow seeds : 8,000 total seeds ::
a.
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1 : 6
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c.
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1 : 3
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b.
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1 : 8
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d.
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1 : 4
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In rabbits, black fur (B) is dominant to brown fur (b). Consider the following cross between two rabbits.
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17. |
Refer to the illustration above. Both of the parents in the cross are
a.
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black.
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c.
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homozygous dominant.
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b.
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brown.
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d.
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homozygous recessive.
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18. |
Refer to the illustration above. The phenotype of the offspring indicated by box “3” would be
a.
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brown.
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c.
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a mixture of brown and black.
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b.
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black.
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d.
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The phenotype cannot be determined.
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19. |
What is the expected phenotypic ratio resulting from a homozygous dominant ´ heterozygous monohybrid cross?
a.
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1:3:1
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c.
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2:1
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b.
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1:2:1
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d.
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1:0
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20. |
Refer to the illustration above. The phenotype represented by the cell labeled “1” is
a.
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round, yellow.
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c.
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wrinkled, yellow.
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b.
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round, green.
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d.
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wrinkled, green.
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21. |
An organism that has inherited two of the same alleles of a gene from its parents is called
a.
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hereditary.
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c.
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homozygous.
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b.
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heterozygous.
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d.
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a mutation.
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22. |
In pea plants, yellow seeds are dominant over green seeds. What would be the expected genotype ratio in a cross between a plant with green seeds and a plant that is heterozygous for seed color?
a.
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1:3
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c.
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4:1
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b.
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1:2:1
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d.
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1:1
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23. |
codominance : both traits are displayed ::
a.
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probability : crosses
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b.
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heterozygous : alleles are the same
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c.
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homozygous : alleles are the same
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d.
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Punnett square : chromosomes combine
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24. |
The difference between a monohybrid cross and a dihybrid cross is that
a.
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monohybrid crosses involve traits for which only one allele exists, while dihybrid traits involve two alleles.
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b.
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monohybrid crosses involve self-pollination, while dihybrid crosses involve cross-pollination.
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c.
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monohybrid crosses involve one gene; dihybrid crosses involve two genes.
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d.
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dihybrid crosses require two Punnett squares; monohybrid crosses need only one.
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25. |
What fraction of the offspring resulting from a heterozygous ´ heterozygous dihybrid cross are heterozygous for both traits?
a.
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9/16
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c.
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3/16
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b.
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1/4
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d.
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1/16
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