chapter 11 biology................, chapter 11, Ap Bio Ch11
Hetrozyguous
Term used to refer to an organism that has two different alleles for the same trait
homozygous
Term used to refer to an organism that has two identical alleles for a particular trait
If white eyes are produced by a recessive allele, what is the likely genotype of a white-eyed individual?
rr
Which of the following is NOT a trait that is the result of, or is affected by, the interaction of more than one gene?
sickle cell anemia
The offspring of a monohybrid testcross would have what possible genotype(s)?
. Aa and aa.
The location on a chromosome where a particular gene is located is known as the:
. locus
If a woman is a carrier for the color-blind recessive allele and her husband is normal, what are their chances that a son will be color-blind?
50% since the mother is the only carrier.
If a human who is a tongue roller (T) and has unattached ear lobes (E) marries a person who cannot roll their tongue and has attached earlobes, could they produce an offspring that was also a non-tongue roller with attached earlobes? What would be the genotype of the first parent? the second parent?
; TtEe; ttee
which statement about the blending concept of inheritance is correct?
A cross between a tall man and a short woman would always produce children of medium height.
In what kind of classic Mendelian cross would you expect to find a ratio of 9:3:3:1 among the F2 offspring? A. monohybrid cross B. dihybrid cross C. testcross D. None of the choices is correct.
B. dihybrid cross
In a classic Mendelian monohybrid cross between a homozygous dominant parent and a homozygous recessive parent, which generation is always completely heterozygous? A. F1 generation B. F2 generation C. F3 generation D. P generation
A. F1 generation
The pedigree chart depicts the inheritance pattern of ___. Circles depict females and squares to depict males. Colored shape represent affected individuals (expressing a trait) and uncolored shapes are unaffected (do not express a trait). A. an autosomal recessive characteristic with both parents being heterozygous B. an autosomal dominant characteristic with both parents being homozygous dominant C. an autosomal recessive characteristic with both parents being homozygous recessive D. none of the above
A. an autosomal recessive characteristic with both parents being heterozygous
The pedigree chart depicts the inheritance pattern of ___. Circles depict females and squares to depict males. Colored shape represent affected individuals (expressing a trait) and uncolored shapes are unaffected (do not express a trait). A. an autosomal recessive characteristic with both parents being heterozygous B. an autosomal dominant characteristic with both parents being homozygous dominant C. an autosomal recessive characteristic with both parents being homozygous recessive D. none of the above
A. an autosomal recessive characteristic with both parents being heterozygous
The F2 offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s)
AA, Aa, and aa.
If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent?
Aa
Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate?
About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross between heterozygotes.
Which characteristic of pea plants were important in their selection as Mendel's research organism?
All of the above were important characteristics in Mendel's selection.
Which characteristic of pea plants were important in their selection as Mendel's research organism?
All of the above were important characteristics in Mendel's selection.
In the use of a Punnett square for genetic results of crossing individuals
All of the choices are correct
As many as 60% of people in malaria-infected regions of Africa have the sickle-cell allele, but only about 10% of the U.S. population of African ancestry carries the allele. Malaria remains a major disease in central Africa but has not been a serious problem in the U.S. for many generations. What is/are the reason(s) for the difference in the percentages and what is a reasonable statement about future percentages?
All of the choices are reasonable.
Computer simulations are sometimes used to demonstrate the outcome of monohybrid fruit fly crosses, where a student can run generation after generation of fruit flies with 100 offspring produced each generation, half male and half female, and a 3-to-1 phenotype ratio (or 75 to 25) in the F1 generation. Compared with real genetics results,
All of the choices are true.
If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent? A. AA B. Aa C. aa D. The answer cannot be determined from this information.
B. Aa
The offspring of a monohybrid testcross would have what possible genotype(s)? A. AA and Aa. B. Aa and aa. C. AA, Aa, and aa. D. AA only. E. aa only.
B. Aa and aa.
Which is NOT true according to Mendel's law of segregation? A. Each individual contains two factors for each trait. B. One factor must be dominant and one factor recessive in each individual. C. Factors separate from each other during gamete formation. D. Each gamete contains one copy of each factor. E. Fertilization restores the presence of two factors.
B. One factor must be dominant and one factor recessive in each individual.
In 1940, two researchers named Weiner and Landsteiner discovered that about 85 percent of the human population sampled possessed a blood cell protein that had been previously detected in Rhesus monkeys. This blood type was labeled Rh positive, and Rh+ was found to be dominant over the absence of the blood factor (Rh). Under normal Mendelian inheritance, which of the following statements is FALSE? A. Two Rh+ parents could have an Rh- child. B. Two Rh- parents could have an Rh+ child. C. An Rh- child would require that both parents be carriers of at least one Rh- gene. D. It is possible with just one pair of parents to have children where some siblings are Rh- and some are Rh+. E. All of the choices are false.
B. Two Rh- parents could have an Rh+ child.
Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis. However, it is possible to assert that _________ resulted in nondisjunction in _________. A. XXY; oogenesis B. XYY; spermatogenesis C. XXX; oogenesis D. XXY; spermatogenesis E. XO; oogenesis
B. XYY; spermatogenesis
What are alleles? A. genes for different traits, such as hair color or eye color B. alternative forms of a gene for a single trait, such as blue eyes or brown eyes C. the locations of genes on a chromosome D. recessive forms of a kind of characteristic carried by genes E. dominant forms of a kind of characteristic carried by genes
B. alternative forms of a gene for a single trait, such as blue eyes or brown eyes
The F2 offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s) A. AA and Aa. B. Aa and aa. C. AA, Aa, and aa. D. AA only. E. Aa only.
C. AA, Aa, and aa.
Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway) are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why? A. The lethal recessive gene may be incompletely dominant. B. Spreading the gene among offspring of both sexes will increase the likelihood it will be sexlinked and expressed. C. The selective-mating of closely related individuals, or inbreeding, increases chances that two recessive genes will "meet" in offspring. D. "Pleiotropy" - the gene that is being selected for this trait may have the second effect of being lethal. E. "Epistasis" - selection for the desired trait may result in "uncovering" the lethal gene.
C. The selective-mating of closely related individuals, or inbreeding, increases chances that two recessive genes will "meet" in offspring.
Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway) are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why? A. The lethal recessive gene may be incompletely dominant. B. Spreading the gene among offspring of both sexes will increase the likelihood it will be sexlinked and expressed. C. The selective-mating of closely related individuals, or inbreeding, increases chances that two recessive genes will "meet" in offspring. D. "Pleiotropy" - the gene that is being selected for this trait may have the second effect of being lethal. E. "Epistasis" - selection for the desired trait may result in "uncovering" the lethal gene.
C. The selective-mating of closely related individuals, or inbreeding, increases chances that two recessive genes will "meet" in offspring.
Women with X-linked disorders always pass the genes for the disorder to _____, while men with X-linked disorders always pass the genes for the disorder to ______. A. only their daughters; only their daughters B. both their daughters and sons; only their sons C. both their daughters and sons; only their daughters D. both their daughters and sons; their daughters and sons
C. both their daughters and sons; only their daughters
A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n) ___________ genotype. A. homozygous dominant B. heterozygous dominant C. homozygous recessive D. any of the choices
C. homozygous recessive
The location on a chromosome where a particular gene is located is known as the: A. allele B. dihybrid C. locus D. diploid E. autosome
C. locus
If a pea plant shows a recessive phenotype, A. the genotype may be TT or Tt. B. the genotype may be Tt or tt. C. the genotype can only be TT. D. the genotype can only be tt. E. the genotype may be TT, Tt, or tt.
D. the genotype can only be tt.
If a pea plant shows a recessive phenotype. A. the genotype may be TT or Tt. B. the genotype may be Tt or tt. C. the genotype can only be TT. D. the genotype can only be tt. E. the genotype may be TT, Tt, or tt.
D. the genotype can only be tt.
Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate? A. All will be green with chlorophyll since that is the dominant trait. B. All will be white and lack chlorophyll since this is self-pollinated. C. About one-half will be green and one-half white since that is the distribution of the genes in the parents. D. About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross between heterozygotes. E. About one-fourth will be green and three-fourths white since it is similar to a monohybrid cross between heterozygotes.
D. About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross between heterozygotes.
Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate? A. All will be green with chlorophyll since that is the dominant trait. B. All will be white and lack chlorophyll since this is self-pollinated. C. About one-half will be green and one-half white since that is the distribution of the genes in the parents. D. About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross between heterozygotes. E. About one-fourth will be green and three-fourths white since it is similar to a monohybrid cross between heterozygotes.
D. About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross between heterozygotes.
In the use of a Punnett square for genetic results of crossing individuals A. all different kinds of sperm are lined up either horizontally or vertically. B. all different kinds of eggs are lined up either horizontally or vertically. C. the results show the offspring's expected genotypes. D. All of the choices are correct E. A and B only.
D. All of the choices are correct
As many as 60 % of people in malaria-infected regions of Africa have the sickle-cell allele, but only about 10% of the U.S. population of African ancestry carries the allele. Malaria remains a major disease in central Africa but has not been a serious problem in the U.S. for many generations. What is/are the reason(s) for the difference in the percentages and what is a reasonable statement about future percentages? A. The presence of malaria in Africa maintains the advantage of the heterozygous sickle-cell trait, and the prevalence of malaria will likely continue to preserve the 60% rate. B. The U. S. percentage may have always been somewhat lower due to immigration from nonmalaria regions, but changes in sites and rates of immigration could occur. C. Lack of widespread malaria in the United States would have made both homozygous and heterozygous carriers of sickle-cell undergo several generations of negative selection, and we should expect this to continue unless innovative therapies give all individuals an equal chance of surviving and reproducing. D. All of the choices are reasonable.
D. All of the choices are reasonable.
The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability. The standard assumption is that tongue-rolling is a dominant allele at a single gene locus. Which of the following would cast doubt on this assumption? A. A teacher reports that after testing her class on the ability to roll their tongue, with very little effort the non-tongue-rollers can learn to also roll their tongues. B. A student who can roll his tongue has a mother and father, both of whom cannot. C. A student who cannot roll his tongue has a mother and father, both of whom can. D. Both A and B are situations that would cast doubt on this assumption.
D. Both A and B are situations that would cast doubt on this assumption.
What aspect of Mendel's background gave him the necessary tools to discover the laws of inheritance?
D. He had studied mathematics and probability.
What aspect of Mendel's background gave him the necessary tools to discover the laws of inheritance? A. He was a monk. B. He was a teacher. C. He lived in Austria. D. He had studied mathematics and probability. E. He corresponded with Charles Darwin.
D. He had studied mathematics and probability.
What is the blending theory of inheritance? A. Mendel's theory of how the traits of parents are passed to offspring through the gametes B. Darwin's theory of how traits are passed from all parts of the parent's body into the gamete to be transmitted to the offspring C. the modern theory of how genetic information is passed from parents to offspring D. an old theory that said that offspring show traits intermediate between those of the parents
D. an old theory that said that offspring show traits intermediate between those of the parents
Since each child of two heterozygous parents has a 1/2 chance of receiving a recessive trait from each parent, A. if the first child is phenotypically recessive, then the next child must be phenotypically dominant. B. if the first child is phenotypically recessive, then the next child has a 3/4 chance of being phenotypically recessive. C. if the first child is phenotypically recessive, then the next child has a 1/2 chance of being phenotypically recessive. D. no matter what the first child's phenotype, the next child will have a 1/4 chance of being phenotypically recessive.
D. no matter what the first child's phenotype, the next child will have a 1/4 chance of being phenotypically recessive.
Haiti is settled by peoples of both African and European ancestry. A young couple, both with mixed ancestry, marry and have several children. The children vary widely in the amount of skin melanin production, with one child being lighter than both parent, and one being darker. The simple explanation for this is A. epistasis. B. multiple alleles are available for the one chromosomal locus that governs skin color. C. the environment affected the phenotype that developed. D. polygenic inheritance. E. gene linkage.
D. polygenic inheritance.
Haiti is settled by peoples of both African and European ancestry. A young couple, both with mixed ancestry, marry and have several children. The children vary widely in the amount of skin melanin production, with one child being lighter than both parent, and one being darker. The simple explanation for this is A. epistasis. B. multiple alleles are available for the one chromosomal locus that governs skin color. C. the environment affected the phenotype that developed. D. polygenic inheritance. E. gene linkage.
D. polygenic inheritance.
Which of the following is NOT a trait that is the result of, or is affected by, the interaction of more than one gene? A. human skin color B. cleft palate C. height D. sickle cell anemia
D. sickle cell anemia
If the probability of event A is 3/4 and the probability of event B is 1/4, then the probability of both A and B occurring at the same time is A. 3/4. B. 1/4. C. 1 or absolute certainty. D. 1/2. E. 3/16.
E. 3/16.
If the parents are AO and BO genotypes for the AB O blood group, their children could include which of the following genotypes? A. AO and BO only B. AO, BO, and AB only C. AA, BB, and AB only D. AO, BO, and OO only E. AO, BO, AB, and OO only
E. AO, BO, AB, and OO only
If the parents are AO and BO genotypes for the ABO blood group, their children could include which of the following genotypes? A. AO and BO only B. AO, BO, and AB only C. AA, BB, and AB only D. AO, BO, and OO only E. AO, BO, AB, and OO only
E. AO, BO, AB, and OO only
Which characteristic of pea plants were important in their selection as Mendel's research organism? A. Peas are easy to cultivate. B. Pea plants have a short generation time. C. Pea plants are self-pollinating but can be cross-fertilized easily. D. Many true-breeding varieties were available. E. All of the above were important characteristics in Mendel's selection.
E. All of the above were important characteristics in Mendel's selection.
In pea plants, the gene for round seed (R) is dominant, and wrinkled seeds (r) are recessive. The endosperm of the pea is also either starchy, a dominant gene (S), or waxy (s). What can be said of a fully heterozygous, dihybrid cross? A. It is impossible to secure offspring that are homozygous for both dominant genes. B. It is impossible to secure offspring that are homozygous for both recessive genes. C. It is impossible to secure offspring that are homozygous for one dominant gene such as round seed and homozygous recessive for the other recessive waxy gene. D. All of these choices are impossible combinations in a dihybrid cross. E. All of these choices are possible combinations in a dihybrid cross.
E. All of these choices are possible combinations in a dihybrid cross.
Unattached earlobes (EE or Ee) are described in the textbook as dominant over attached earlobes (ee). A couple both have unattached earlobes. Both notice that one of their parents on both sides has attached earlobes (ee). Therefore, they correctly assume that they are carriers for attached earlobes (Ee). The couple proceeds to have four children. A. They can be certain that three will be heterozygous and one homozygous recessive. B. If the first three are heterozygous, the fourth must be homozygous recessive. C. The children must repeat the grandparents' genotype (Ee). D. All children must have unattached earlobes since both parents possess the dominant gene for it. E. Two heterozygous, one homozygous recessive and one homozygous dominant is a likely outcome, but all heterozygous, or two, three or all four homozygous are also possible.
E. Two heterozygous, one homozygous recessive and one homozygous dominant is a likely outcome, but all heterozygous, or two, three or all four homozygous are also possible.
Unattached earlobes (EE or Ee) are described in the textbook as dominant over attached earlobes (ee). A couple both have unattached earlobes. Both notice that one of their parents on both sides has attached earlobes (ee). Therefore, they correctly assume that they are carriers for attached earlobes (Ee). The couple proceeds to have four children. A. They can be certain that three will be heterozygous and one homozygous recessive. B. If the first three are heterozygous, the fourth must be homozygous recessive. C. The children must repeat the grandparents' genotype (Ee). D. All children must have unattached earlobes since both parents possess the dominant gene for it. E. Two heterozygous, one homozygous recessive and one homozygous dominant is a likely outcome, but all heterozygous, or two, three or all four homozygous are also possible.
E. Two heterozygous, one homozygous recessive and one homozygous dominant is a likely outcome, but all heterozygous, or two, three or all four homozygous are also possible.
Which of the following crosses would always result in offspring that only display the dominant phenotype? A. TT x tt B. Tt x Tt C. TT x TT D. Tt x tt E. both A and C
E. both A and C
If individuals exhibiting a dominant phenotype are crossed and produce only offspring with the dominant phenotype, what would be the logical genotype of the parents? A. both are homozygous recessive B. one is heterozygous and one is homozygous dominant C. both are homozygous dominant D. both are heterozygous E. both B and C
E. both B and C
Phenotype
Physical characteristics of an organism
The most common lethal genetic disease among Caucasians is A. neurofibromatosis. B. Tay-Sachs disease. C. phenylketonuria. D. albinism. E. cystic fibrosis.
E. cystic fibrosis.
The water buttercup produces thin leaves underwater, but those same tissues will produce broad leaves above the water. Individuals in the 1800's (when hunger and childhood diseases were common) averaged slightly over five feet tall, but their offspring in the 1900's were substantially taller on the average. This reflects the influence of A. polygenic inheritance. B. epistasis. C. gene linkage. D. genotype having no relationship to phenotype. E. environmental factors on gene expression
E. environmental factors on gene expression
In a classic Mendelian monohybrid cross between a homozygous dominant parent and a homozygous recessive parent, which generation is always completely heterozygous?
F1 generation
Cystic fibrosis and Niemann-Pick Disease are common autosomal dominant disorders. True False
False
If an individual is heterozygous for a particular trait, the gametes that individual produces will contain 3/4 dominant and 1/4 recessive alleles.
False
Genotype
Genetic makeup of an organism
What aspect of Mendel's background gave him the necessary tools to discover the laws of inheritance?
He had studied mathematics and probability.
Which is associated with the inability to produce factor VIII in the blood?
Hemophilia A
Codominance
Situation in which both alleles of a gene contribute to the phenotype of organism
Incomplete dominance
Situation in which one allele is not completely dominate over another
Which of the following crosses would always result in offspring that only display the dominant phenotype? A. TT x tt B. Tt x Tt C. TT x TT D. Tt x tt E. both A and C
TT x tt and TT x TT
Which of the following crosses would always result in offspring that only display the dominant phenotype?
TT x tt and TT x TT
Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway) are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why?
The selective-mating of closely related individuals, or inbreeding, increases chances that two recessive genes will "meet" in offspring.
Each gamete carries one factor, now called an allele, for each inherited trait. True False
True
In a case of incomplete dominance, the phenotypic ratio of the F2 generation is the same as the genotypic ratio. True False
True
Polygenic traits such as height or weight are often influenced by the environment of the organism.
True
In 1940, two researchers named Weiner and Landsteiner discovered that about 85 percent of the human population sampled possessed a blood cell protein that had been previously detected in Rhesus monkeys. This blood type was labeled Rh positive, and Rh+ was found to be dominant over the absence of the blood factor (Rh). Under normal Mendelian inheritance, which of the following statements is FALSE?
Two Rh- parents could have an Rh+ child.
Unattached earlobes (EE or Ee) are described in the textbook as dominant over attached earlobes (ee). A couple both have unattached earlobes. Both notice that one of their parents on both sides has attached earlobes (ee). Therefore, they correctly assume that they are carriers for attached earlobes (Ee). The couple proceeds to have four children.
Two heterozygous, one homozygous recessive and one homozygous dominant is a likely outcome, but all heterozygous, or two, three or all four homozygous are also possible.
Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis. However, it is possible to assert that _________ resulted in nondisjunction in _________.
XYY; spermatogenesis
Women with X-linked disorders always pass the genes for the disorder to _____, while men with X-linked disorders always pass the genes for the disorder to ______.
both their daughters and sons; only their daughters
Which allele combination represents a recessive individual?
aa
What are alleles?
alternative forms of a gene for a single trait, such as blue eyes or brown eyes
What is the blending theory of inheritance?
an old theory that said that offspring show traits intermediate between those of the parents
The most common lethal genetic disease among Caucasians is
cystic fibrosis.
Punnett square
diagram showing the gene combinations that might result from a genetic cross
In what kind of classic Mendelian cross would you expect to find a ratio of 9:3:3:1 among the F2 offspring?
dihybrid cross
Which is NOT true according to Mendel's law of segregation?
each individual.
A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n) ___________ genotype.
homozygous recessive
When a round fruit plant is crossed with a long fruit plant their offspring are oval. What is the best explanation for this scenario?
incomplete dominance
The reason why some individuals who inherit polydactyly (having an extra digit on the hand or feet) but do not express the trait is due to
incomplete penetrance
When an individual of African descent marries and has children with an individual of European descent their children often have a mid shade of skin color. This can best be described as ___________.
poly genetic inheritance
Haiti is settled by peoples of both African and European ancestry. A young couple, both with mixed ancestry, marry and have several children. The children vary widely in the amount of skin melanin production, with one child being lighter than both parents, and one being darker. The simple explanation for this is
polygenic inheritance.
Which of the following scenarios would not have been used by Mendel during his research?
relied on his memory to remember his data
If a pea plant shows a recessive phenotype,
the genotype can only be tt.
Multiple alleles
three or more alleles of the same gene
When crossing a true-breeding red snapdragon flower with a true-breeding white flower of the same species, we secure all pink offspring. This would seem to support the pre-Mendel view that inheritance is a blending of parental traits. However, Mendel and conventional wisdom agree that "blending" of parental traits is not correct and that particles of inheritance are actually involved because
under blending theory, over many generations only the average (or pink flowers) would remain; there would be no way to get back to pure red and whiteand and. it is possible to cross the pink F-1 generation and secure a predictable proportion of pure red and white flowers again, which is not accounted for under the blending theoryare true
The particulate theory of inheritance
was proposed by Mendel and is based on particles or hereditary units we now call
The particulate theory of inheritance
was proposed by Mendel and is based on particles or hereditary units we now call genes