Biology - Chapter 14

Which of the following scenarios describes an example of epistasis? Question 9 options: A) In many mammals one genotype (ee) prevents any fur color from developing. B) In fruit flies white eyes can be due alleles of a gene on the X chromosome or a combination of other genes. C) In cacti, there several genes control the type of spines. D) Albino corn snake result from animals having recessive genotypes for each of two genes.

A In many mammals one genotype (ee) prevents any fur color from developing.

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. Also, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. What phenotypes would be expected from a cross between a true-breeding sharp-spined cactus and a spineless cactus? Question 7 options: A) all sharp-spined progeny B) 50% sharp-spined, 50% dull-spined progeny C) 25% sharp-spined, 50% dull-spined, 25% spineless progeny D) It is impossible to determine the phenotypes of the progeny.

A all sharp-spined progeny

Skin color in a certain species of fish is inherited via a single gene with four different alleles. Each allele confers a unit of color darkness such that having allele S1 confers one unit of color, S2 has two units, S3 has three units, and S4 confers four units. A fish of this type has the genotype S1S3, and its mate has the genotype S2S4. What proportion of their offspring would be expected to have five units of color? Question options: A) 1/2 B) 0 C) 1/4 D) 1/8

A) 1/2

In a cross of individuals who both possess this genotype, AaBbCc, what proportion of the offspring is predicted to have the genotype, AABBCC? Question options: A) 1/64 B) 1/16 C) 1/8 D) 1/4

A) 1/64

When Mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow-seeded. Which of the following genotypic ratios was expected when Mendel crossed the F1 yellow-seeded plants with green-seeded plants? Question options: A) 1:1 B) 1:2:1 C) 9:3:3:1 D) 3:1

A) 1:1

If the parent or offspring genotypes or phenotypes are known, the pattern of inheritance can be predicted. Two organisms, with genotypes BbDD and BBDd, are mated. Assuming independent assortment of the two loci, which of the following genotypic ratios in offspring would occur? Question options: A) 1BBDD: 1 BbDD: 1 BBDd: 1 BbDd B) 9 BBDD: 3 BbDD: 3 BBDd: 1 bbdd C) 1 BBDD: 2 BbDd: 1bbdd D) 1 BBDD: 1 bbdd

A) 1BBDD: 1 BbDD: 1 BBDd: 1 BbDd

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. A second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. If cacti heterozygous for both traits, SsNn, were allowed to self-pollinate, the offspring would segregate into which of the following phenotype ratios? Question options: A) 9 sharp-spined:3 dull-spined:4 spineless B) 3 sharp-spined:1 spineless C) 1 sharp-spined:2 dull-spined:1 spineless D) 1 sharp-spined:1 dull-spined:1 spineless

A) 9 sharp-spined:3 dull-spined:4 spineless

In a particular plant, green seed color is dominant to blue. If two plants with green seeds were crossed and resulted in 302 green and 98 blue seed plants, what was the most probable genotype of each parent? Question 11 options: A) Gg × Gg B) GG × Gg C) G × G D) gg × Gg

A) Gg × Gg

Which of the following statements correctly explains the observation that parents with two different phenotypes produced offspring with a phenotype that is a blend of the two parental varieties? Question options: A) Neither of the parental alleles is dominant over the other. B) Both of the parents have dominant alleles. C) Both of the parents are homozygous at that locus D) Neither of the parental alleles is expressed in the offspring

A) Neither of the parental alleles is dominant over the other.

One of two major forms of neurofibromatosis results from inheriting a dominant allele of a gene with affected individuals having phenotypes that range from mild to very severe. Which of the following is the best explanation for why a young child is the first in her family to be diagnosed with a severe form of the condition? Question options: A) One of the parents has a mild expression of the gene. B) The mother carries the gene but does not express it. C) The condition skipped a generation in the family. D) The child has one more chromosome than either of the parents.

A) One of the parents has a mild expression of the gene.

Which of the following inheritance patterns describes the ability of a single allele to have multiple phenotypic effects? Question 3 options: A) pleiotropy B) multiple alleles C) epistasis D) incomplete dominance

A) pleiotropy

Which of the following describes why Mendel continued some of his experiments into the F2 or F3 generation? Question options: A) Collecting data from more generations allowed him to obtain a larger number of offspring. B) Following multiple generations allowed him to determine whether a recessive trait would reappear. C) Data from the F1 generation did not allow him to distinguish which alleles were segregating D) Determining whether a dominant trait would reappear required multiple dihybrid crosses.

B Following multiple generations allowed him to determine whether a recessive trait would reappear.

Phenylketonuria is an inherited disease caused by a recessive allele. If a woman and her husband are both carriers, what is the probability that their first child will be a girl without phenylketonuria? Question options: A) 1/4 B) 3/8 C) 3/16 D) 3/4

B) 3/8

Which of the following statements correctly explains the fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment? Question 19 options: A) The diploid number of chromosomes in the pea plants was seven. B) All of the genes controlling the traits were on different chromosomes. C) All of the genes controlling the traits had only two different alleles. D) None of the traits obeyed the law of segregation.

B) All of the genes controlling the traits were on different chromosomes.

Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes eye problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information? Question 12 options: A) It is epistatic. B) It is pleiotropic. C) It is dominant. D) It is recessive.

B) It is pleiotropic.

Which of the following statements best describes the addition rule of probability? Question options: A) It is the probability that two or more independent events will occur simultaneously. B) It is the probability that either one of two independent events will occur. C) It is the probability that a trait requires two or more generations to be seen. D) It is the probability of producing two or more heterozygous offspring.

B) It is the probability that either one of two independent events will occur.

Which of the following relationships among alleles of a single gene best explains the observation that a single change in the gene encoding α-keratin results in chickens with frizzled feathers, increased food consumption, higher heart rate and delayed sexual maturity? Question 13 options: A) Incomplete dominance B) Pleiotropy C) Codominance D) Homozygous locus

B) Pleiotropy

Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately break down the amino acid phenylalanine. This amino acid is not naturally produced by humans. Which of the following treatments would be most effective for people with PKU? Question 16 options: A) Feed the individual the substrate that can be metabolized into phenylalanine. B) Regulate the individual's diet to severely limit the uptake of phenylalanine. C) Feed the individual the missing enzymes in a regular cycle, such as twice per week. D) Feed the individual an excess of the missing product.

B) Regulate the individual's diet to severely limit the uptake of phenylalanine.

Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which individuals look very old even as young children, experience very early senility and severe coronary artery disease, and have a life expectancy of 13 years. Which of the following statements represents the most likely assumption regarding this disorder? Question options: A) Each patient will have had at least one affected grandparent or parent. B) The disorder may be due to mutation in a single protein-coding gene. C) The disorder may be due to the patient being exposure to an environmental mutagen as an infant. D) The disorder will increase in frequency in successive generations within a family.

B) The disorder may be due to mutation in a single protein-coding gene.

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. Also, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. The relationship between genes S and N is an example of which of the following inheritance patterns? Question 17 options: A) codominance B) epistasis C) incomplete dominance D) pleiotropy

B) epistasis

Which of the following best describes how an individual with genotype AaBbCCDdEE can make haploid gametes with different genotypes? Question 5 options: A) dominant alleles tend to be inherited together B) the inheritance of a particular copy of one chromosome does not affect the inheritance of a different chromosome C) mutations during meiosis form new alleles that are incorporated into the gametes D) crossing over during prophase I leads to increased genetic diversity

B) the inheritance of a particular copy of one chromosome does not affect the inheritance of a different chromosome

Albinism is a recessive trait where an individual does not produce the pigment melanin. A man and woman who both produce melanin have one child out of three who has albinism. What are the genotypes of the man and woman? Question options: A) One parent must be heterozygous; the other parent can be homozygous dominant, homozygous recessive, or heterozygous. B) One parent must be homozygous for the recessive allele; the other parent can be homozygous dominant, homozygous recessive, or heterozygous. C) Both parents must be heterozygous. D) One parent must be homozygous dominant; the other parent must be heterozygous.

C Both parents must be heterozygous.

Which of the following sentences state a significant conclusion that Gregor Mendel drew from his experiments with pea plants? Question options: A) Genes are composed of DNA. B) There is considerable genetic variation in garden peas. C) Traits are inherited in discrete units and are not the result of "blending." D) Recessive genes occur more frequently in the F1 generation than do dominant ones.

C Traits are inherited in discrete units and are not the result of "blending."

Feather color in budgies is determined by two different genes: Y for pigment on the outside of the feather, and B for pigment on the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. A blue budgie is crossed with a white budgie. Which of the following results in the offspring is most possible? Question options: A) green offspring only B) blue offspring only C) blue and white offspring D) white offspring only

C blue and white offspring

Having polydactyly (extra digits on hands and feet) is a dominant trait. A man has polydactyly. His wife and oldest daughter do not have polydactyly. The couple's second child has polydactyly. What is the probability that their next (third) child will have extra digits? Question 8 options: A) 3/4 B) 1/16 C) 1/2 D) 1/8

C) 1/2

In a certain species of diploid fish a single gene controls skin color. Researchers have found four different alleles of this gene within the fish population. How many different gamete genotypes are possible in an individual of this species? Question options: A) 4 B) 16 C) 2 D) 8

C) 2

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? Question options: A) 4 B) 64 C) 8 D) 16

C) 8

Why did all of the F1 offspring of Mendel's purple and white flowered pea cross always look like one of the two parental varieties? Question 1 options: A) No genes interacted to produce a new unique phenotype. B) Each allele affected phenotypic expression. C) One allele was dominant. D) The traits blended together during fertilization.

C) One allele was dominant.

A gene for the MN blood group has codominant alleles M and N. If both children in a family are of blood type M, which of the following situations is possible? Question 14 options: A) neither parent can have the N allele B) both children are heterozygous for this gene C) each parent is either M or MN D) each parent must be type M

C) each parent is either M or MN

A radish is a root vegetable that produces flowers that may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant trait. If true-breeding red-flowered, long radishes long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to exhibit which of the following phenotypes? Question options: A) purple and oval B) white and long C) purple and long D) red and oval

C) purple and long

In pea plants, the tall phenotype is dominant to the dwarf phenotype. If a heterozygous pea plant is crossed with a homozygous tall pea plant, what is the probability that the offspring will be dwarf in size?Question 6 options: A) 0.5 B) 0.25 C) 1 D) 0

D) 0

Use the figure and the following description to answer the question.In a particular plant, leaf color is controlled by gene locus D. Plants with at least one allele D have dark green leaves, and plants with the homozygous recessive dd genotype have light green leaves. A true-breeding, dark-leaved plant is crossed with a light-leaved one, and the F1 offspring is allowed to self-pollinate. The predicted outcome of the F1 cross is diagrammed in the Punnett square shown in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square.Which of the boxes marked 1-4 correspond to plants that will be true-breeding? A) 1 only B) 2 and 3 only C) 1, 2, 3, and 4 D) 1 and 4 only

D) 1 and 4 only

Albinism is a recessive trait where an individual does not produce the pigment melanin. A man and woman both produce melanin, but both have one parent with albinism. What is the probability that their first child will have albinism? Question 18 options: A) 0 B) 1/2 C) 1 D) 1/4

D) 1/4

What fraction of the offspring from a cross between two animals with the genotype AaBbCc are expected to be homozygous recessive for the three traits? Question 15 options: A) 1/8 B) 1/16 C) 1/4 D) 1/64

D) 1/64

In human blood types, Rh positive is a trait that shows simple dominance over Rh negative. The Rh phenotype is recorded by stating "positive" or "negative" after the individuals ABO blood type. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Which of the following phenotypes is possible for the father? Question 20 options: A) AB negative B) O negative C) A negative D) B positive

D) B positive

Human civilizations developed practices regarding inheritance before the scientific grounding of the practices had been determined. Which of the following genetic principles provides scientific support for the societal taboo against closely related people having children? Question 2 options: A) A common environment can influence the severity of harmful traits. B) Not all harmful dominant alleles can affect reproduction. C) Recessive disorders are relatively common. D) Heterozygous loci can mask harmful traits in an individual.

D) Heterozygous loci can mask harmful traits in an individual.

Which of the following statements correctly describes how Mendel explained why traits disappeared in the F1 generation and then reappeared in the F2 generation? Question options: A) Members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait. B) The mechanisms controlling the appearance of traits in the F1 and F2 plants were different. C) New mutations were frequently generated in the cross that generated F2 offspring, causing traits that had been lost in the F1 to reappear in the F2. D) Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1.

D) Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1.

A brown dog crossed with a yellow dog produced 12 brown offspring. A second brown individual was obtained. When the yellow dog was crossed with this animal, six brown and six yellow offspring were born. Which of the following best explains the results of the second cross? Question 10 options: A) yellow and brown are codominant B) yellow is a recessive trait; brown is codominant C) yellow is a dominant trait; brown is incompletely dominant D) yellow is a recessive trait; brown is a dominant trait

D) yellow is a recessive trait; brown is a dominant trait

The following question refers to the figure of a family's pedigree chart, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle.What is the genotype of individual II-5? Question options: A) Ww B) ww or Ww C) ww D) WW

NOT B ww or Ww

Ten plants of the same genotype are planted in a large flower garden. Later that year, some of the ten plants have blue flowers and others have pink flowers. This can be best explained by which of the following statements? Question options: A) the allele for blue hydrangea is completely dominant over the allele for pink hydrangea B) environmental factors such as soil pH affect the phenotype C) multiple alleles are involved in color determining flower color D) the alleles are codominant

NOT C) multiple alleles are involved in color determining flower color