bio chapter 14
In humans, ABO blood types refer to glycoproteins in the membranes of red blood cells. There are three alleles for this autosomal gene: IA, IB, and i. The IA allele codes for the A glycoprotein, The IB allele codes for the B glycoprotein, and the i allele doesn't code for any membrane glycoprotein. IA and IB are codominant, and i is recessive to both IA and IB. People with type A blood have the genotypes IAIA or IAi, people with type B blood are IBIB or IBi, people with type AB blood are IAIB, and people with type O blood are ii. If a woman with type AB blood marries a man with type O blood, which of the following blood types could their children possibly have? A) A and B B) AB and O C) A,B, and O D) A,B,AB,and O
A) A and B
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? A)All of the genes controlling the traits behaved as if they were on different chromosomes. B)None of the traits obeyed the law of segregation. C)The diploid number of chromosomes in the pea plants was seven. D)All of the genes controlling the traits were located on the same chromosome.
A) All of the genes controlling the traits behaved as if they were on different chromosomes.
Which of the following phenotypes is an example of polygenic inheritance? A) skin pigmentation in humans B) white and purple flower color in peas C) pink flowers in snapdragons D) the ABO blood group in humans
A) skin pigmentation in humans
Skin color in a certain species of fish is inherited by a single gene with four different alleles. How many different types of gametes would be possible in this organism? A)4 B)8 C)16 D)2
A)4
Which of the following statements is correct in describing the terms monohybrid cross and dihybrid cross? A)A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied. B)A monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations. C)A monohybrid cross results in a 9:3:3:1 ratio, whereas a dihybrid cross gives a 3:1 ratio D)A monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents.
A)A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.
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? A)Each parent is either M or MN. B)Each parent must be type M. C)Both children are heterozygous for this gene. D)Neither parent can have the N allele.
A)Each parent is either M or MN.
Which of the following statements about independent assortment or segregation is correct? A)The law of independent assortment describes the behavior of two or more genes relative to one another. B)The law of independent assortment is accounted for by observations of prophase I of meiosis. C)The law of segregation is accounted for by anaphase of mitosis. D)The law of segregation describes the behavior of two or more genes relative to one another.
A)The law of independent assortment describes the behavior of two or more genes relative to one another
A cross between an individual with orange eyes and green skin and an individual with black eyes and white skin is an example of a _____ cross. A)dihybrid B)monohybrid C)difficult D)test E)trihybrid
A)dihybrid
The result of the following cross indicates the orange eyes are _____ black eyes. A)recessive to B)co-dominant to C)larger than D)dominant to E)incompletely dominant to
A)recessive to
What is the probability of producing the genotype AABBCC in a cross of individuals who both possess this genotype: AaBbCc? A)1/8 B)1/64 C)1/16 D)1/4
B) 1/64
Given the following genotypes for two parents, AABBCc × AabbCc, assume that all traits exhibit simple dominance and independent assortment. What proportion of the progeny of this cross will be expected to phenotypically resemble the first parent with the genotype AABBCc? A)1 B)3/4 C)3/8 D)1/4
B) 3/4
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? A) 4 B) 8 C) 16 D) 64
B) 8
The figure shows the pedigree for a family. Dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis. Males are represented by squares, females by circles. From this pedigree, this trait seems to be inherited ________. A) as a result of epistasisas B) an autosomal dominant C) as an autosomal recessive D) from mothers
B) as an autosomal dominant
One of two major forms of a human condition called neurofibromatosis (NF1) is inherited as a dominant gene, although it may range from mildly to very severely expressed. Which of the following is the best explanation for why a young, affected child is the first in her family to be diagnosed? A) the mother carries the gene but does not express it B) one of the parents has a mild expression of the gene C) the condition skipped a generation in the family D) the child has one more chromosome than either of the parents
B) one of the parents has a mild expression of the gene
In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (CRCW) offspring of red (CRCR) and white (CWCW) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white? A) red x white B) roan x roan C) white x roan D) red x roan
B) roan x roan
If B represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the phenotypic ratio of a cross between a heterozygous black-eyed MendAlien and an orange-eyed MendAlien? A)3 black : 1 orange B)1 black : 1 orange C)1 black : 0 orange D)0 black : 1 orange E)1 black : 3 orange
B)1 black : 1 orange
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails? A) 1/16 B) 3/8 C) 1/2 D) 9/16
C) 1/2
Albinism is a recessive trait. A man and woman both show normal pigmentation, but both have one parent who has albinism (without melanin pigmentation). What is the probability that their first child will have albinism? A) 0 B) 1/2 C) 1/4 D) 1
C) 1/4
Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers, and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort independently. Among the F2 offspring, what is the probability of producing plants with white axial flowers? A) 9/16 B) 1/16 C) 3/16 D) 1/4
C) 3/16
An obstetrician knows that one of her patients is a pregnant woman whose fetus is at risk for a serious disorder that is detectable biochemically in fetal cells. The obstetrician would most reasonably offer which of the following procedures to her patient? A)blood transfusion B)karyotyping of the womans somatic cells C)amniocentesis or CVS D)X-ray
C) amniocentesis or CVS
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? A) it is recessive B) it is dominant C) it is pleiotropic D) it is epistatic
C) it is pleoitropic
Phenylketonuria is an inherited disease caused by a recessive autosomal allele. If a woman and her husband are both carriers, what is the probability that their first child will be a phenotypically normal girl? A)1/16 B)1/4 C)3/8 D)3/16
C)3/8
Which of the following calculations require the use of the addition rule of probability? A)Calculate the probability of children with both cystic fibrosis and polydactyly when parents are each heterozygous for both genes. B)Calculate the probability of black offspring from the cross AaBb × AaBb, where B is the symbol for black C)Calculate the probability of a child having either sickle-cell anemia or cystic fibrosis if parents are each heterozygous for both. D)Calculate the probability of each of four children having cystic fibrosis if the parents are both heterozygous.
C)Calculate the probability of a child having either sickle-cell anemia or cystic fibrosis if parents are each heterozygous for both
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? A)HhTt B)Hh C)HT D)T
C)HT
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants? A)Genes are composed of DNA. B)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." D)There is considerable genetic variation in garden peas.
C)Traits are inherited in discrete units and are not the result of "blending."
A phenotypic ratio of 9:3:3:1 in the offspring of a cross indicates that _____. A)both parents are homozygous dominant B)one parent is homozygous dominant and one parent is homozygous recessive C)both parents are heterozygous for both genes D)one parent is homozygous dominant and one parent is heterozygous E)one parent is heterozygous and one parent is homozygous recessive
C)both parents are heterozygous for both genes
The individual with genotype AaBbCCDdEE can make many kinds of gametes. Which of the following correctly describes why this situation is possible? A)recurrent mutations form new alleles B)there is a tendency for dominant alleles to segregate together C)different possible assortment of chromosomes into gametes occurs D)crossing over during prophase I leads to genetic variety
C)different possible assortment of chromosomes into gametes occurs
The result of the following cross indicates that the genotype of the male parent is _____. A)Rr B)R C)rr D)r E)RR
C)rr
The following question refers to the pedigree chart in the figure for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle.What is the probability that individual III-1 is Ww? A)1/4 B)3/4 C)2/4 D)1
D) 1
2) Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? A) prophase 1 of meiosis B) anaphase 2 of meiosis C) metaphase 2 of meiosis D) anaphase 1 of meiosis
D) anaphase 1 of meiosis
Which of the following statements best describes the addition rule of probability? A)the probability of producing two or more heterozygous offspring B) the probability that two or more independent events will occur simultaneously C)The likelihood that a trait is due to two or more meiotic events D)the probability that either one of two independent events will occur
D) the probability that either one of two independent events will occur
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 F2 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), 2, 3, and 4 B)2 and 3 only C)1 only D)1 and 4 only
D)1 and 4 only
Black eyes are dominant to orange eyes, and green skin is dominant to white skin. Sam, a MendAlien with black eyes and green skin, has a parent with orange eyes and white skin. Carole is a MendAlien with orange eyes and white skin. If Sam and Carole were to mate, the predicted phenotypic ratio of their offspring would be _____. A)3 black eyes, green skin : 3 black eyes, white skin : 9 orange eyes, green skin : 1 orange eyes, white skin B)9 black eyes, green skin : 3 black eyes, white skin : 3 orange eyes, green skin : 1 orange eyes, white skin C)There is insufficient information to determine Sam's genotype. D)1 black eyes, green skin : 1 black eyes, white skin : 1 orange eyes, green skin : 1 orange eyes, white skin E)1 black eyes, green skin : 3 black eyes, white skin : 3 orange eyes, green skin : 9 orange eyes, white skin
D)1 black eyes, green skin : 1 black eyes, white skin : 1 orange eyes, green skin : 1 orange eyes, white skin
When Mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow-seeded. When he took these F1 yellow-seeded plants and crossed them to green-seeded plants, what genotypic ratio was expected? A)3:1 B)1:2:1 C)1:1:1:1 D)1:1
D)1:1
A black guinea pig crossed with a guinea pig with albinism produced 12 black offspring. When the albino was crossed with a second black animal, six blacks and six albinos were obtained. What is the best explanation for this genetic situation? A)Albinism is a dominant trait; black is incompletely dominant. B)Albinism is a recessive trait; black is codominant. C)Albinism and black are codominant. D)Albinism is a recessive trait; black is a dominant trait.
D)Albinism is a recessive trait; black is a dominant trait.
In human blood types, Rh positive is a trait that shows simple dominance over Rh negative. 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? A)AB negative B)A negative C)O negative D)B positive
D)B positive
That each gamete contains a single allele of the eye color gene is an illustration of _____. A)Mendel's law of independent assortment B)only Darwin's theory of natural selection C)Beadle and Tatum's one gene - one enzyme hypothesis D)Mendel's law of segregation only E)Both Mendel's law of segregation and Mendel's law of independent assortment.
D)Mendel's law of segregation only
Which of the following statements is a correct explanation for the observation that all offspring exhibit a phenotype for a particular trait that appears to be a blend of the two parental varieties? A)The genes for the trait are dominant in both of the parents. B)The genes for the trait are recessive in both of the parents. C)The genes are linked and do not separate during meiosis. D)Neither of the parental genes is dominant over the other.
D)Neither of the parental genes is dominant over the other
Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an F2 generation. The results were as follows: 6,022 yellow and 2,001 green (8,023 total). Which of the following statements correctly describes the relationship of the allele for green seeds to the allele for yellow seeds? A)The two alleles are codominant. B)The two alleles exhibit incomplete dominance. C)The green allele is dominant to the yellow allele. D)The green allele is recessive to the yellow allele.
D)The green allele is recessive to the yellow allele.
Mendel's law of independent assortment has its basis in which of the following events of meiosis I? A)crossing over of homologous pairs of chromosomes B)synapsis of homologous chromosomes C)the division of cells at telophase D)alignment of pairs of homologous chromosomes along the middle of the cell
D)alignment of pairs of homologous chromosomes along the middle of the cell
In order to determine the genotype of a MendAlien with black eyes and green skin, you would cross this individual with a(n) _____ individual. A)BBgg B)BBGG C)BbGg D)bbgg E)bbGG
D)bbgg
The observed distribution of alleles into gametes is an illustration of _____. A)Mendel's law of independent assortment B)onlyMendel's law of segregation only C)Eimer's principle D)Thienemann's rule E)Mendel's laws of segregation and independent assortment
E) Mendel's laws of segregation and independent assortment
if B represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the genotypic ratio of a cross between a heterozygous black-eyed MendAlien and an orange-eyed MendAlien? A)0 homozygous black (BB): 0 heterozygote (black) (Bb): 1 homozygous orange (bb) B)1 homozygous black (BB): 1 heterozygote (black) (Bb): 1 homozygous orange (bb) C)2 homozygous black (BB): 1 heterozygote (black) (Bb): 1 homozygous orange (bb) D)1 homozygous black (BB): 0 heterozygote (black) (Bb): 1 homozygous orange (bb) E)0 homozygous black (BB): 1 heterozygote (black) (Bb): 1 homozygous orange (bb)
E)0 homozygous black (BB): 1 heterozygote (black) (Bb): 1 homozygous orange (bb)
In a situation in which genes assort independently, what is the ratio of the gametes produced by an AaBB individual? A)1 A : 1 B B)3 AA : 1 BB C)3 AB : 1 ab D)3 A : 1 B E)1 AB : 1 aB
E)1 AB : 1 aB
Which of these is a testcross? A)A? x A? B)A? x Aa C)aa x aa D)A? x AA E)A? x aa
E)A? x aa
A BbGg x bbgg cross yields a phenotypic ratio of approximately 5 black eyes, green skin : 5 orange eyes, white skin : 1 black eyes, white skin : 1 orange eyes, green skin. Which of the following best explains these results? A)The genes for eye color and skin color are co-dominant. B)The heterozygous individual is male, and the homozygous individual is female. C)Mendel's laws of segregation and independent assortment are being violated. D)Mendel's law of segregation is being violated. E)Mendel's law of independent assortment is being violated.
E)Mendel's law of independent assortment is being violated.
The result of the following cross indicates that the genotype of the female parent is _____. A)rr B)r C)R D)Rr E)RR
E)RR
An individual heterozygous for eye color, skin color, and number of eyes mates with an individual who is homozygous recessive for all three characters; what would be the expected phenotypic ratio of their offspring? [Hint: B = black eyes, b = orange eyes; G = green skin, g = white skin; C = two eyes, c = one eye] A)9 orange eyes, green skin, two eyes : 9 orange eyes, green skin, one eye : 9 orange eyes, white skin, two eyes : 1 orange eyes, white skin, one eye B)1 black eyes, green skin, two eyes : 1 black eyes, green skin, one eye : 1 black eyes, white skin, two eyes : 1 black eyes, white skin, one eye : 1 orange eyes, green skin, two eyes : 1 orange eyes, green skin, one eye : 1 orange eyes, white skin, two eyes : 1 orange eyes, white skin, one eye C)1 black eyes, green skin, two eyes : 1 black eyes, green skin, one eye : 1 black eyes, white skin, two eyes : 1 orange eyes, green skin, two eyes : 1 orange eyes, white skin, two eyes : 1 orange eyes, white skin, one eye D)9 black eyes, green skin, two eyes : 3 black eyes, green skin, one eye : 3 black eyes, white skin, two eyes : 1 black eyes, white skin, one eye : 9 orange eyes, green skin, two eyes : 3 orange eyes, green skin, one eye : 3 orange eyes, white skin, two eyes : 1 orange eyes, white skin, one eye E)9 black eyes, green skin, two eyes : 3 black eyes, green skin, one eye : 3 black eyes, white skin, two eyes : 1 black eyes, white skin, one eye
B)1 black eyes, green skin, two eyes : 1 black eyes, green skin, one eye : 1 black eyes, white skin, two eyes : 1 black eyes, white skin, one eye : 1 orange eyes, green skin, two eyes : 1 orange eyes, green skin, one eye : 1 orange eyes, white skin, two eyes : 1 orange eyes, white skin, one eye
Use the table 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 F2 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 with dark leaves? A)2 and 3 B)1, 2, and 3 C)1 only D)4 only
B)1, 2, and 3
In the following cross the genotype of the female parent is BbGg. What is the genotype of the male parent? [Hint: B = black eyes, b = orange eyes, G = green skin, g = white skin] A)BbGG B)BBGg C)BbGg D)BBGG E)bbGG
B)BBGg
Gray seed color in peas is dominant to white. Assume that Mendel conducted a series of experiments where plants with gray seeds were crossed among themselves, and the following progeny were produced: 302 gray and 98 white. What is the most probable genotype of each parent? A)GG × Gg B)Gg × Gg C)GG × gg D)gg × Gg
B)Gg × Gg
Why did all of the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? A)Each allele affected phenotypic expression. B)One allele was dominant. C)No genes interacted to produce the parental phenotype. D)The traits blended together during fertilization.
B)One allele was dominant.
Which of the following statements correctly describes how Mendel accounted for the observation that traits had disappeared in the F1 generation and then reappeared in the F2 generation? 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)Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1. C) New mutations were frequently generated in the F2 progeny, causing traits that had been lost in the F1 to reappear in the F2. D)The mechanism controlling the appearance of traits was different between the F1 and the F2 plants.
B)Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1.
The result of the following cross indicates that genotypically the offspring _____. A)exhibit a 1 RR : 2 Rr : 1 rr ratio B)are all Rr C)exhibit a 3 RR : 1 rr ratio D)are all rr E)are all RR
B)are all Rr
What is the genotype of the parent with orange eyes and white skin? (Note: orange eyes are recessive.) A)BbGg B)bbgg C)bbGG D)BBGG E)bbGg
B)bbgg
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? A)the alleles are codominant B)environmental factors such as soil pH affect the phenotype C)the allele for blue hydrangea is completely dominant over the allele for pink hydrangea D)the knowledge that multiple alleles are involve
B)environmental factors such as soil pH affect the phenotype
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. At the same time, 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? A)codominance B)epistasis C)pleiotropy D) incomplete dominance
B)epistasis
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 part of the radish we eat may be oval or long, with long being the dominant trait. If true-breeding red long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to exhibit which of the following phenotypes? A)red and long B)purple and long C)white and long D)purple and oval
B)purple and long
Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately metabolize 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? A) feed them the substrate that can be metabolized into phenylalanine B) regulate the diet of the affected persons to severly limit the uptake of phenylalanine C) feed the patients the missing enzymes in a regular cycle, such as twice per week D) feed the patients an excess of the missing product
B)regulate the diet of the affected persons to severly limit the uptake of phenylalanine
