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Which allele combination represents a male who has an X-linked recessive disorder?
Hemophilia is an X-linked recessive disorder that is passed through generations and can be traced by using a pedigree.
In the pedigree that is shown, which represents Irene's allele combination?
The results of Thomas Hunt Morgan’s last cross are shown in the Punnett square below.
Which of Thomas Hunt Morgan's hypotheses was valid based on these results?
White eyes are lethal in female Drosophila.
White eyes are lethal in male Drosophila.
Female Drosophila with white eyes are homozygous recessive.
White eyes are the dominant trait in female Drosophila.
Glaucoma is a leading cause of blindness. Studies have linked a common form of glaucoma to three genes and more than 20 genetic loci. Which best describes glaucoma?
a recessive trait that requires multiple recessive alleles to be expressed
a polygenic trait that is influenced by the alleles of several genes
a codominant trait that is expressed more often when more dominant alleles are present
a dominant trait that depends on the presence of only one of many dominant alleles
Mary has type A blood. Her son Bill has type AB blood. Which blood type does Bill's dad have if he is homogenous for blood type?
If a person has type B blood, which statement describes the antibodies present in his or her blood?
Only anti-A antibodies are present.
Only anti-B antibodies are present.
Both anti-A and anti-B antibodies are present.
Neither anti-A nor anti-B antibodies are present.
Which was most likely an effect on society that resulted from improvements in blood handling during World War I and World War II?
More soldiers died as a result of incorrect blood typing.
More soldiers who had lost a limb returned home.
More donations were needed as a result of poor storage techniques.
More organizations spoke out against the war.
In peas, yellow seed color (Y) is dominant to green seed color (y). Which describes an organism that has nonidentical alleles for seed color?
yy and has green seeds
Yy and has yellow seeds
YY and has yellow seeds
Yy and has green seeds
A purebred plant that has yellow flowers is crossed with a purebred plant that has white flowers. All the offspring have yellow flowers. Which conclusion about yellow flowers is supported by these results?
Yellow flower color is a dominant trait.
Yellow flower color is a recessive trait.
Yellow flower color is a heterozygous trait.
Yellow flower color is a monohybrid trait.
Round seeds and yellow seed color are dominant to wrinkled seeds and green seed color. What is the probability of having offspring that have wrinkled seeds and yellow seed color for the cross RRYY x RrYy?
In peas, yellow seed color (Y) is dominant to green seed color (y). A homozygous green pea plant is crossed with a heterozygous yellow pea plant. What is the predicted phenotypic ratio of the offspring?
50 percent yellow, 50 percent green
50 percent Yy, 50 percent yy
100 percent yellow, 0 percent green
100 percent Yy, 0 percent yy
Which Punnett square represents a cross between two parents that are heterozygous for purple flowers?
Gregor Mendel used pea plants that were heterozygous for each of two traits—seed color and seed shape—to generate a dihybrid cross. The phenotypic ratio of the resulting offspring was nine with round and yellow seeds, three with round and green seeds, three with wrinkled and yellow seeds, and one with wrinkled and green seeds. From these results, what could Mendel conclude?
Traits are inherited as pairs, sets, or groups.
Traits that are dominant mask traits that are recessive.
Gametes carry one allele for each trait.
Traits are passed independently of one another.
In a dihybrid cross for round and yellow seeds (RrYy x RrYy), what is the probability of having green and wrinkled seeds?
Which type of scientific statement is defined as a hypothesis or group of hypotheses that can be accepted as true based on repeated experimentation with similar results?
Which of Mendel’s generations was allowed to self-pollinate?
F1 generation and F2 generation
P generation and F2 generation
A scientist is studying fruit fly wings. Straight wings are dominant, and curly wings are recessive. Which statement correctly describes the F1 generation if a straight-winged parent is crossed with a curly-winged parent and if both parents are true breeding?
The offspring will have two genes for straight wings.
The offspring will produce only gametes that have genes for curly wings.
The offspring will have one allele for straight wings and one allele for curly wings.
The offspring will have only one kind of allele for the gene that determines wing type.
A pea plant exhibits a recessive trait. Which statement is most likely true about the plant?
The plant is identical to its parent plant.
The plant has different alleles for the gene that codes for the trait.
The plant has two identical alleles for the gene that codes for the trait.
The plant does not have the same genes for the trait as its parent plant.
In the F2 generation of Mendel’s crosses,
all plants had the dominant trait.
half of the plants had the dominant allele.
all plants had both the dominant and recessive alleles.
one in four plants had two alleles for the recessive trait.
Red-green color blindness is an X-linked recessive disorder that is passed through generations and can be traced by using a pedigree.
Which individuals in the pedigree are identified and labeled carriers for red-green color blindness?
Lisa and Monica
Sam, Tim, Bella, and Joshua
Ben, Jenny, Mike, Carol, Katie, and Chris
Ben and Lisa
Suzanne has type A– blood. Which blood type could she receive in a blood transfusion?
Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. A pansy that is homozygous for purple flowers (PP) is crossed with a pansy that is homozygous for pink flowers (pp).
Which genotypes will be included for the offspring in the Punnett square for this cross?
PP, Pp, and pp
PP and pp
PP and Pp
Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. A parakeet that is heterozygous for blue feathers (dominant) is crossed with a parakeet that is homozygous for white feathers (recessive).
According to the Punnett square for this cross, what percentage of offspring is predicted to have blue feathers?
Pea plants can have yellow seeds or green seeds. Which conclusion about the meaning of Y is correct if the allele combination Yy is for yellow seeds?
yellow and dominant
green and recessive
yellow and recessive
green and dominant
Unattached earlobes is a dominant trait, E. A parent who is homozygous for unattached earlobes is crossed with a parent who is homozygous for attached earlobes. Which describes the genotypes of their offspring?
100 percent Ee
100 percent unattached earlobes
100 percent ee
100 percent attached earlobes
In the F1 generation of a Mendelian cross,
only the dominant trait is visible.
only the recessive trait is visible.
neither the dominant nor recessive trait is visible.
both the dominant and recessive traits are visible.
If a scientist wanted to follow Mendel’s experiment with a different kind of plant, which type of plant would she examine?
A plant that cannot self-pollinate.
A plant that has only recessive alleles.
A plant that has three alleles for a trait.
A plant that has only two alleles for a trait.