Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Chapter 3, Problem 35P
Suppose that blue flower color in a plant species is controlled by two genes, A and B. The dominant alleles A and B specify proteins that function in the pathways shown below. The A and B proteins are both required to make blue pigment from a colorless precursor. A and B proteins also independently inhibit the production of blue pigment from a different colorless precursor; that is, the presence of either protein A or protein B is sufficient to prevent blue pigment production from precursor 2. The recessive mutant alleles a and b specify no protein. Two different pure-breeding mutant strains with white flowers were crossed, and complementation was observed so that all the F were blue.
| a. | What are the genotypes of each white mutant strain and the F1? |
| b. | If the F1 are selfed, what would be the |
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Explain how (a) the absence of class B gene expression produces the flower structures seen in class B mutants (see Figure 22.15c) and (b) the absence of class C gene expression produces the structures seen in class C mutants (see Figure 22.15d).
Suppose that you are studying the role of Protein B, which you believe plays a role in regulating PCD/Apoptosis in mice. You create two lines of mutant mice. One (bb) is homozygous for a loss-of-function allele of gene B. The other (Bb) is heterozygous, with one wild-type allele and one loss-of function allele. Initially you pay particular attention to two phenotypes of the resulting mice:(i) The morphology of their paws (see picture)(ii) The size of their brains & shape of their skulls. The bb mice have unusually large brains and unusual protrusions from their skulls.
Suggest one other aspect of mouse morphology or physiology that you might expect to be altered in the absence of Protein B. Briefly explain your reasoning.
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Suppose that you are studying the role of Protein B, which you believe plays a role in regulating PCD/Apoptosis in mice. You create two lines of mutant mice. One (bb) is homozygous for a loss-of-function allele of gene B. The other (Bb) is heterozygous, with one wild-type allele and one loss-of function allele. Initially you pay particular attention to two phenotypes of the resulting mice:(i) The morphology of their paws (see picture) (ii) The size of their brains & shape of their skulls. The bb mice have unusually large brains and unusual protrusions from their skulls. Based on these data, does it appear that Protein B, when present and active, favors or inhibits PCD/Apoptosis?Briefly explain your reasoning. The answer should address both the paw and brain/skull data.
Chapter 3 Solutions
Genetics: From Genes to Genomes
Ch. 3 - For each of the terms in the left column, choose...Ch. 3 - In four-oclocks, the allele for red flowers is...Ch. 3 - The Aa heterozygous snapdragons in Fig. 3.3 are...Ch. 3 - Recall from Chapter 2 Fig. 2.20 that Mendels R...Ch. 3 - In the fruit fly Drosophila melanogaster, very...Ch. 3 - A cross between two plants that both have yellow...Ch. 3 - In radishes, color and shape are each controlled...Ch. 3 - A wild legume with white flowers and long pods is...Ch. 3 - Assuming no involvement of the Bombay phenotype in...Ch. 3 - Several genes in humans in addition to the ABO...
Ch. 3 - Alleles of the gene that determines seed coat...Ch. 3 - One of your fellow students tells you that there...Ch. 3 - In a population of rabbits, you find three...Ch. 3 - In clover plants, the pattern on the leaves is...Ch. 3 - Fruit flies with one allele for curly wings Cy and...Ch. 3 - In certain plant species such as tomatoes and...Ch. 3 - In a species of tropical fish, a colorful orange...Ch. 3 - People heterozygous for normal and nonfunctional...Ch. 3 - Using old Fugate family Bibles and the Perry...Ch. 3 - A rooster with a particular comb morphology called...Ch. 3 - A black mare was crossed to a chestnut stallion...Ch. 3 - Filled-in symbols in the pedigree that follows...Ch. 3 - You perform a cross between two true-breeding...Ch. 3 - a. How would you describe inheritance of flower...Ch. 3 - Suppose the intermediate called Colorless...Ch. 3 - Explain the difference between epistasis and...Ch. 3 - The dominant allele H reduces the number of body...Ch. 3 - Secretors genotypes SS and Ss secrete their A and...Ch. 3 - Normally, wild violets have yellow petals with...Ch. 3 - A woman who is blood type B has a child whose...Ch. 3 - The following table shows the responses of blood...Ch. 3 - Three different pure-breeding strains of corn that...Ch. 3 - In mice, the AY allele of the agouti gene is a...Ch. 3 - A student whose hobby was fishing pulled a very...Ch. 3 - Suppose that blue flower color in a plant species...Ch. 3 - This problem examines possible biochemical...Ch. 3 - Considering your answers to Problem 36, does the...Ch. 3 - You picked up two mice one female and one male...Ch. 3 - Figure 3.21 and Fig. 3.28b both show traits that...Ch. 3 - Three genes in fruit flies affect a particular...Ch. 3 - The garden flower Salpiglossis sinuata painted...Ch. 3 - In foxgloves, three different petal phenotypes...Ch. 3 - In a culture of fruit flies, matings between any...Ch. 3 - Prob. 44PCh. 3 - A couple wants to know the probability that their...Ch. 3 - This problem illustrates why classical geneticists...Ch. 3 - Prob. 47PCh. 3 - Familial hypercholesterolemia FH is an inherited...Ch. 3 - You have come into contact with two unrelated...Ch. 3 - Polycystic kidney disease is a dominant trait that...Ch. 3 - Identical monozygotic twins have similar, but not...Ch. 3 - Using each of the seven coat color genes discussed...
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