Genetics CH5 McgrawHill Smartbook

CH 5 smartbook question answers Which two fundamental laws of inheritance did Mendel discover? law of segregation and law of independent assortment Match each pattern of inheritance with its description. Follows a strict dominant/recessive relationship,Traits for which males inherit only one allele while females inherit two alleles,Alleles that have the potential to cause death,Pattern in which both alleles are expressed in the hete A cell with at least one copy of a wild-type allele will typically produce ______ of the protein specified by this allele. a functional version When more than one wild-type allele occurs in a population, the phenomenon is called . genetic polymorphism,polymorphism Over 10 million Americans are heterozygous for the allele for Cystic Fibrosis, while about 30,000 people with homozygous recessive genotypes have the disease. Cystic Fibrosis results from a deficiency of a chlo wild-type; mutant What are the two fundamental laws of inheritance discovered by Mendel? law of independent assortment,law of segregation Which description matches each pattern of inheritance? Heterozygote has intermediate phenotype.,Heterozygote expresses both alleles simultaneously.,Trait occurs in only one of the two sexes.,Trait is inherited by both sexes but with di ff erent dominant/recessive patterns.,Failure The most commonly occurring allele in a population is called the - allele. wild type,type A population that contains more than one wild-type allele demonstrates genetic ______. polymorphism In the general population, 1/150 people are carriers for the allele for Tay-Sachs disease. A child with the disease is born to healthy parents who are unaware of their carrier status. The allele that prevents the dise wild-type; mutant When more than one wild-type allele occurs in a population, the phenomenon is called . genetic polymorphism,polymorphism Rarely-occurring alleles that have genetic changes making them defective in protein production are called ______ alleles. mutant Brittle bone disease is caused by a mutation in a gene that codes for collagen fibers. The product of the mutant allele binds to normal collagen and disrupts proper fiber formation. The mutation can be describe dominant-negative The most commonly occurring allele in a population is called the - allele. wild type,type Familial hypercholesterolemia is due to a lack of receptors for low-density-lipoproteins on the surfaces of cells. Both homozygous dominant individuals and heterozygous individuals su ff er from the disease. Eve haploinsu ffi ciency The pattern observed when a heterozygote does not show the trait associated with the dominant allele is . incompletely,penetrant When a preexisting allele is changed to a new version that no longer codes for a functional protein, the new allele is called a allele. loss-of-function The type of mutation in which a protein produced by a mutant allele acts against a normal protein is called a - mutation. dominant negative,negative Himalayan coloring in rabbits is due to a dominant allele that codes for a tyrosinase enzyme which participates in the production of the dark pigment melanin. In cold temperatures, dark coloring is only found in Tyrosinase is a temperature-sensitive enzyme. If a heterozygous individual shows a disease phenotype despite having one functional allele, the inheritance pattern is called . haploinsu ffi cience Suppose a genetic test shows that a woman has inherited the dominant BRCA1 allele that causes breast cancer. If she does not develop breast cancer in her lifetime, the phenomenon is called . incomplete penetrance,penetrance In fruit flies, the para mutation causes a change in a sodium channel necessary for conducting nerve signals. Mutant flies have normal movement at 22oC but become immediately paralyzed at 29oC. The paralys temperature-sensitive allele The pattern observed when a heterozygote does not show the trait associated with the dominant allele is . incompletely,penetrant When a preexisting allele is changed to a new version that no longer codes for a functional protein, the new allele is called a allele. loss-of-function The ability to prevent the symptoms of phenylketonuria by restricting the diets of patients who inherit the disease is an example of e ff ects on a phenotype. nutritional The type of mutation in which a protein produced by a mutant allele acts against a normal protein is called a - mutation. dominant negative,negative Which pattern is shown by a heterozygous individual that has a phenotype that is intermediate between the phenotypes of the dominant and recessive homozygotes? incomplete dominance If a heterozygous individual shows a disease phenotype despite having one functional allele, the inheritance pattern is called . haploinsu ffi cience In chickens, feather color can be black or splash (white with black spots). If a black rooster is crossed to a splash hen, the o ff spring show an intermediate blue color. If a splash rooster is crossed to a blue hen, w 1/2 Suppose a genetic test shows that a woman has inherited the dominant BRCA1 allele that causes breast cancer. If she does not develop breast cancer in her lifetime, the phenomenon is called . incomplete penetrance,penetrance What is the name for the situation where heterozygotes have greater reproductive success than either of the two homozygotes? Overdominance The e ff ect of phenylketonuria, an autosomal recessive disorder in which individuals are unable to metabolize phenylalanine, can be altered by a restricted diet with limited amounts of phenylalanine. This is an ex environmental e ff ects on gene expression Which outcome in this Punnett square shows the e ff ects of incomplete dominance? B A patient with sickle cell disease may experience a painful episode leading to tissue and organ damage because cells carrying hemoglobin S ______. form abnormal crescent shapes that block capillaries, depriving nearby cells of oxygen In chickens, feather color can be black or splash (white with black spots). If a black rooster is crossed to a splash hen, the o ff spring show an intermediate blue color. If a blue rooster is crossed to a blue hen, wh 1/4 The ability to prevent the symptoms of phenylketonuria by restricting the diets of patients who inherit the disease is an example of e ff ects on a phenotype. nutritional Individuals with the HbA HbS genotype do not develop malaria because ______. the presence of hemoglobin S prevents the malarial parasite from reproducing within their bodies Instead of the Mendelian ratio of 3:1, the ratio of phenotypes for o ff spring from a cross between two individuals who are heterozygous for sickle cell disease is : : . one,two,one Individuals with an HbS HbS genotype su ff er from sickle cell anemia because they produce ______, a variant that causes their red blood cells to form ______. hemoglobin S; crescent shapes when oxygen concentration is low Even though it leads to sickle cell disease in homozygous individuals, the allele HbS is retained in some populations because it confers resistance to for heterozygotes. malaria Among the children of two parents with the HbA HbS genotype, what percentage is expected to be una ff ected by sickle cell anemia and resistant to malaria? 50% While causing sickle-cell anemia in homozygous individuals, the product of the HbS allele provides resistance to malaria in individuals with the HbA HbS genotype. This advantage to heterozygotes demonstrate overdominance The situation where a heterozygote has a characteristic that makes it more likely than either homozygous individual to reproduce in a given environment is called . heterozygote advantage Instead of the Mendelian ratio of 3:1, the ratio of phenotypes for o ff spring from a cross between two individuals who are heterozygous for sickle cell disease is : : . one,two,one In corn plants, the enzyme alcohol dehydrogenase functions as a homodimer, where the two subunits can be identical or slightly di ff erent. One type of subunit is stable but somewhat inactive, while another type overdominance When an allele causes a disease in the homozygous recessive genotype but confers resistance to a di ff erent disease in heterozygotes, the phenomenon is called ______. overdominance A single gene for white coloring on the coats of dogs has four alleles with a hierarchy of dominance. Various combinations of these alleles can lead to solid coat, Irish-spotting, piebald-spotting, and white coats multiple alleles Even though it leads to sickle cell disease in homozygous individuals, the allele HbS is retained in some populations because it confers resistance to for heterozygotes. malaria Which of the surface antigens related to blood type would be found on the red blood cells of an individual with the IAIB genotype? Each red blood cell would carry both surface antigen A and surface antigen B. Suppose a mother with the IAi genotype and a father with the IBi genotype have two children, one with a codominant genotype and one with a genotype demonstrating complete dominance. The children's geno Codominant = IAIB; Complete dominance = IBi Suppose protein C functions as a homodimer, where the two subunits can be identical (C1C1 or C2C2) or slightly di ff erent (C1C2). Further suppose that the C1C2 homodimer is more stable than either homodime heterozygote advantage Which phenomenon is observed in a population when three or more alleles can be found for a single gene? multiple alleles For which of the following genotypes would the e ff ects of codominance be observed in the individual's phenotype? IAIB Suppose a mother with the IAi genotype and a father with the IBi genotype have one child with type A blood and one child with type AB blood. Which is the best description of the observed genetic patterns? Codominance is observed for the child with type AB blood while complete dominance is observed for the child with type A blood. Suppose a man with type A blood and a woman with type B blood have a child with type O blood. What are the chances that they could have a child with type AB blood at a later time? 25% Suppose protein C functions as a homodimer, where the two subunits can be identical (C1C1 or C2C2) or slightly di ff erent (C1C2). Further suppose that the C1C2 homodimer is more stable than either homodime heterozygote advantage The di ff erence between type A and type B blood is produced by ______. glycosyl transferase enzymes with di ff erent activities What are the chances that a man with type O blood and a woman with type AB blood could have a child with type O blood? 0% Which two of the following a ff ect the transmission pattern of sex-linked genes? the sex of the o ff spring,whether the gene is on the X or Y chromosome Which inheritance pattern is shown for a trait occurring in one sex but not in the opposite sex? sex-limited inheritance The development of specific sex organs, such as the presence of testes in human males and ovaries in human females is due to - inheritance. sex,limited The enzyme glycosyl transferase is the product of the gene for ABO blood type. In determining the phenotype of individuals inheriting specific alleles of this gene, the product of the i allele is ______ and the prod inactive; active In humans, the transmission pattern of sex-linked genes depends on whether the gene is on the or chromosome and on the sex of the o ff spring. X,Y A trait that is expressed in only one sex and not seen in the opposite sex shows ______ inheritance. sex-limited For humans, the presence of ovaries in females and testes in males is an example of ______ inheritance. sex-limited Male birds often have more ornate and colorful feathering patterns than female birds. This is an example of ______. sexual dimorphism An allele that can lead to the death of an individual is a(n) ______ allele. lethal The development of specific sex organs, such as the presence of testes in human males and ovaries in human females is due to - inheritance. sex,limited A phenomenon involving animals of the same species, but of opposite sexes, that have di ff erent physical features is called . sex,dimorphism A lethal allele usually shows a(n) ______ inheritance pattern. recessive In humans, the transmission pattern of sex-linked genes depends on whether the gene is on the or chromosome and on the sex of the o ff spring. X,Y A gene that codes for a product that is necessary for the survival of an organism is called a(n) ______ gene. essential An allele that leads to the death of the organism only under specific environmental influences is called a(n) ______ lethal allele. conditional A gene that produces a beneficial product that is not absolutely required for survival of the organism is called a(n) ______ gene. nonessential Parents can unknowingly pass on a dominant lethal allele for Huntington disease to their o ff spring because the ______. disease symptoms often do not appear until after the parent has had children A temperature-sensitive allele that causes the death of an organism only with exposure to a specific range of temperatures is a(n) ______ lethal allele. conditional A phenomenon involving animals of the same species, but of opposite sexes, that have di ff erent physical features is called . sex,dimorphism G6PD deficiency results from a deficiency of an enzyme that is especially important for protecting red blood cells from harmful oxidizing agents. People with G6PD deficiency can live healthy lives but can die fro conditionally Suppose that there are two male mice who are homozygous for the same allele. They are raised under the same environmental conditions: receiving the same types of foods in cages exposed to the same range semilethal allele Huntington disease is a lethal condition for which symptoms begin to appear in middle age. The age at which a person begins to show disease symptoms is called the of . age of onset,onset Why does an organism that inherited one or more temperature-sensitive lethal alleles survive at low temperatures? The protein product of the temperature-sensitive allele can function at low temperatures. The allele for sickle cell anemia leads to multiple changes in the individual's phenotype, including the type of hemoglobin produced, the shape of red blood cells, the onset of anemia, and reduced susceptibility t pleiotropy Which of the following can explain why pleiotropy occurs? expression of one gene that a ff ects cell function in more than one way,expression of one gene at di ff erent stages of development,expression of one gene in di ff erent cell types For dog coat color, the dominant S+allele results in full pigmentation while the recessive sIallele leads to white patches on the legs and belly called Irish spotting. Suppose that a cross between a fully pigmented S+sI G6PD deficiency results from a deficiency of an enzyme that is especially important for protecting red blood cells from harmful oxidizing agents. People with G6PD deficiency can live healthy lives but can die fro conditionally Dark pigmentation of fur in dogs depends on the production of ______ by cells called ______. melanin; melanocytes The pattern where one gene a ff ects many traits is called . pleiotropy Which choice does not represent an explanation for pleiotropy? expression of two genes that a ff ect cell function in more than one way For dog coat color, the dominant S+S+<math xmlns=\http://www.w3.org/1998/Math/MathML\"><msup><mi>S</mi><mo>+</mo></msup></math>allele results in full pigmentation while the recessive sIsI<math 1/4 A dog's fur will have white patches if cells called do not produce the pigment melanin. melanocyte An allele that causes death in some, but not all individuals in a population is a allele. semi-lethal For dog coat color, the dominant S+S+<math xmlns=\http://www.w3.org/1998/Math/MathML\"><msup><mi>S</mi><mo>+</mo></msup></math>allele results in full pigmentation while the recessive sIsI<math S+sIS+sI<math xmlns=\http://www.w3.org/1998/Math/MathML\"><msup><mi>S</mi><mo>+</mo></msup><msup><mi>s</mi><mi>I</mi></msup></math>" White spots occur in the coats of dogs as a result of a decrease in the number of that are responsible for producing dark pigment. melanoblasts The pattern where one gene a ff ects many traits is called . pleiotropy For Australian parakeets, the dominant allele of one gene causes yellow-colored feathers. The dominant allele of another gene causes blue pigment to be made, resulting in green-colored feathers. This is an exa gene interaction Coloration of the feathers of parakeets is controlled by two genes. The dominant allele Y for one gene leads to yellow coloration. The corresponding recessive allele y results in white feathers. The dominant alle 1/16 A dog's fur will have white patches if cells called do not produce the pigment melanin. melanocyte For summer squash, the dominant allele for one gene leads to yellow color while the recessive allele for this gene leads to green color. When the genotype of a second gene is either homozygous dominant or he epistasis For the white spotting phenotype in dogs, the regions with fewer melanocytes and lighter coloration are located _____. in areas farthest away from the spinal cord The pattern where allelic variants of two di ff erent genes a ff ect a single trait is called . gene,redundancy Coloration of the feathers of parakeets is controlled by two genes. The dominant allele Y for one gene leads to yellow coloration. The corresponding recessive allele y results in white feathers. The dominant alle 3/16 When Blue-Eyed Mary plants inherit at least one dominant allele for a gene for flower color, their petals are blue to match their name. If plants are homozygous recessive for a second gene, however, they develo recessive epistasis White spots occur in the coats of dogs as a result of a decrease in the number of that are responsible for producing dark pigment. melanoblasts The following pathway is proposed to explain the inheritance of purple flower color in pea plants: Colorless Precursor → Colorless Intermediate → Purple Pigment. A dominant allele for gene C provides an enzyme the cc genotype exerts epistasis over the Pp genotype, preventing purple color formation Suppose that the covering on corn kernels can have a purple color due to the dominant allele P of gene 1. Alleles of gene 2 can mask this color, with the dominant allele C having no e ff ect but genotype cc chang recessive epistasis For summer squash, the dominant allele Y for gene 1 leads to yellow color while the recessive allele y leads to green color. Alleles of gene 2 can prevent color formation, with the dominant allele W leading to wh 12/16 For harebell plants, dominant alleles for two separate genes are needed to produce blue petal color. Suppose gene 1 has alleles P and p and gene 2 has alleles B and b. Only plants with at least one P allele and a 7/16 The following pathway is proposed to explain the inheritance of purple flower color in pea plants: Colorless Precursor → Colorless Intermediate → Purple Pigment. A dominant allele for gene C provides an enzyme complementation occurs in the purple-petaled plant, showing that the mutations preventing color in the white plants are in di ff erent genes The pattern where allelic variants of two di ff erent genes a ff ect a single trait is called . gene,redundancy Feather coloration in Australian parakeets is under the control of two genes. The dominant allele for gene Y leads to production of psittacofulvin for yellow coloration, while the recessive allele y prevents yellow gene,modification For sweet pea plants, two genes are involved in purple coloration of flower petals. At least one copy of each of the dominant alleles C and P are required for purple color while the genotypes cc or pp result in wh recessive epistasis Suppose that the covering on corn kernels can have a purple color due to the dominant allele P of gene 1. The genotype pp leads to a colorless covering. Alleles of gene 2 can mask the purple color, with the dom 7/16 When one gene can compensate for the loss of function of another gene, the phenomenon is called . gene redundancy,redundance In fruit flies, dominant alleles for two di ff erent genes are required for red eye color. Suppose gene 1 has alleles R and r and gene 2 has alleles E and e. Only flies with at least one R allele and at least one E allele w 9/16 Two genes controlling the synthesis of di ff erent pigments are responsible for feather coloration in Australian parakeets. The dominant allele Y for one gene leads to production of psittacofulvin for yellow colorat Gene A modifies the expression of gene Y. Suppose loss-of-function mutations in two separate genes do not produce any phenotypic e ff ects but combining the two loss-of-function mutations in one organism shows a di ff erence in phenotype. What is the gene redundancy One gene can compensate for the loss of function of another gene in cases where a duplicate gene called a(n) has arisen over evolutionary time or when the function of another can be increased to compensat paralog,protein Feather coloration in Australian parakeets is under the control of two genes. The dominant allele for gene Y leads to production of psittacofulvin for yellow coloration, while the recessive allele y prevents yellow gene,modification Genes that may di ff er slightly in sequence but were derived by duplication during evolution are called . paralog When one gene can compensate for the loss of function of another gene, the phenomenon is called . gene redundancy,redundance Which of the following demonstrate gene redundancy? An increase in function of one protein to compensate for the loss of function of a similar one.,A gene duplication event where a paralog can carry out the function of a missing gene. Human hemoglobin is a complex of four protein chains produced by two di ff erent genes, one for alpha-hemoglobin and one for beta-hemoglobin. These genes have sequence di ff erences but similarities suggest paralogs One gene can compensate for the loss of function of another gene in cases where a duplicate gene called a(n) has arisen over evolutionary time or when the function of another can be increased to compensat paralog,protein Genes that may di ff er slightly in sequence but were derived by duplication during evolution are called . paralog 1