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28 Cards in this Set
- Front
- Back
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What is the difference between a monohybrid cross and a dihybrid cross?
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A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid only one.
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What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
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Traits are inherited in discrete units, and are not the results of "blending."
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Two characters that appear in a 9:3:3:1 ratio in the F2generation should have which of the following properties?
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The genes controlling the characters obey the law of independent assortment.
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Which of the following about the law of segregation is false?
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It is a method that can be used to determine the number of chromosomes in a plant
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Mendel's second law of independentassortment has its basis in which of the following events of meiosis I?
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Alignment of tetrads at the equator
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Given the parentsAABBCc×AabbCc, assume simple dominance and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent?
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3/4
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Labrador retrievers are black, brown, or yellow. In a cross of a black female with a brown male, results can be either all black puppies, 1/2 black to 1/2 brown puppies, or 3/4 black to 1/4 yellow puppies.
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Epistasis (2 or more genes affecting a phenotype) is involved.
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How many genes would be responsible for the coats in the Labrador retriever question?
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2
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In one type cross of black × black, the results were as follows:
9/16 black 4/16 yellow 3/16 brown The genotype aabb must result in which of the following? |
Yellow
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Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white- flowered plant yields all-purple offspring. The partof the radish we eat may be oval or long, with long being the dominant characteristic.
In the F2generation of the above cross, which of the following phenotypic ratios would be expected? |
6:3:3:2:1:1
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A 1:2:1 phenotypic ratio in the F2generation of a monohybrid cross is a sign of
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incomplete dominance
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Tallness (T) in snapdragons is dominant to dwarfness (t), while red (R) flower color is dominant to white (r). The heterozygous condition results in pink (Rr) flower color. A dwarf, red snapdragon is crossed with a plant homozygous for tallness and white flowers. What are the genotype and phenotype of the F1individuals?
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TtRr–tall and pink
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Skin color in a certain species of fish is inherited via a single gene with four different alleles. How many different types of gametes would be possible in this system?
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4
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If doubly heterozygous SsNn cactuses were allowed to self-pollinate, the F2 would segregate in which of the following ratios?
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9 sharp-spined : 3 dull-spined : 4 spineless
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A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.
Which of the following is a possible partial genotype for the son? Which of the following is a possible genotype for the mother? |
IBi
IAi B positive for the father |
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Which describes the ability of a single gene to have multiple phenotypic effects?
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Pleiotropy
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Which describes the ABO blood group system?
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Multiple alleles
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Which of the following terms best describes when the phenotype of the heterozygote differs from the phenotypes of both homozygotes?
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Incomplete dominance
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Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Whichof the following terms best describes this?
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Pleiotropy
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Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following?
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Environmental factors such as soil pH
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Which of the following provides an example of epistasis?
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In rabbits and many other mammals, one genotype(cc) prevents any fur color from developing
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Most genes have many more than two alleles. However, which of the following is also true?
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There may still be only two phenotypes for the trait
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People with sickle-cell trait
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are heterozygous for the sickle-cell allele.
are usually healthy. have increasedresistance to malaria. produce normal and abnormal hemoglobin. |
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The frequency of heterozygosity for the sickle cell anemia allele is unusually high,
presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? |
Darwin's explanation of natural selection
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Cystic fibrosis (CF) is a Mendelian disorder in the human population that is inherited as a recessive. Two normal parents have two children with CF. The probability of their next child being normal for this characteristic is which of the following?
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1/4
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Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot
appropriately metabolize a particular amino acid. This amino acid is not otherwise produced by humans. Therefore the most efficient and effective treatment is which of the following? |
Regulate the diet of the affected persons to severely limit the uptake of the amino acid.
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Hutchinson-Gilford progeria is anexceedingly rare human genetic disorder in which there is very early senility, and death, usually of coronary artery disease, at an average age of approximately 13. Patients, who look very old even as children, do not live to reproduce. Which of the following represents the most likely assumption?
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The disorder may be due to mutation in a single protein-coding gene
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One of two major forms of a human condition called neurofibromatosis (NF 1) is inherited as a dominant, although it may be either mildly to very severely expressed. If a young child is the first in her family to be diagnosed, which of the following is the best explanation?
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One of the parents has very mild expression of the gene
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