Human Heredity: Principles and Issues (MindTap Course List)
11th Edition
ISBN: 9781305251052
Author: Michael Cummings
Publisher: Cengage Learning
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Chapter 10, Problem 4QP
Questions 4 through 6 refer to the following hypothetical pathway in which substance A is converted to substance C by enzymes 1 and 2. Substance B is the intermediate produced in this pathway:
a. If an individual is homozygous for a null mutation in the gene that codes for enzyme 1, what will the result be?
b. If an individual is homozygous for a null mutation in enzyme 2, what will the result be?
c. What if an individual is heterozygous for a dominant mutation in which enzyme 1 is overactive?
d. What if an individual is heterozygous for a mutation that abolishes the activity of enzyme 2 (a null mutation)?
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Leber’s Hereditary Optic Neuropathy (LHON) is a disease that involves degeneration of neural cells in the retina and results in loss of central vision. The disease is caused by mutations in any one of three genes in the mitochondrial genome that encode proteins involved in oxidative phosphorylation. In a genetic counseling clinic, a woman and her husband seek advice on the potential that any of their children would be afflicted with LHON. The husband's mother and father, both exhibit symptoms of the disease, but the woman does not. What is a reasonable advising statement to make?
a.
The couple should be advised that all of their children are likely to display symptoms of LHON.
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There is not enough information to advise this couple.
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The couple should be advised that none of their children will be affected.
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The couple should be advised that all their male children will display symptoms of LHON, but female children will be unaffected.
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The couple should be…
Leber’s Hereditary Optic Neuropathy (LHON) is a disease that involves degeneration of neural cells in the retina and results in loss of central vision. The disease is caused by mutations in any one of three genes in the mitochondrial genome that encode proteins involved in oxidative phosphorylation. In a genetic counseling clinic, a woman and her husband seek advice on the potential that any of their children would be afflicted with LHON. The husband's mother and father, both exhibit symptoms of the disease, but the woman does not. What is a reasonable advising statement to make?
A genetic disease called glucose-6-phosphate dehydrogenase deficiency is inherited in a manner similar to that of sickle-cell anemia except that it occurs most frequently in males. The defective enzyme cannot keep erythrocytes supplied with sufficient amounts of the antioxidant molecule NADPH NADPH protects cell membranes and other cellular structures from oxidation. Describe in general terms the inheritance pattern of this molecular disease. Why do you think that the antimalarial drug primaquine, which stimulates peroxide formation, results in devastating cases of hemolytic anemia in carriers of the defective gene? Does it surprise you that this genetic anomaly is commonly found in African and Mediterranean populations?
Chapter 10 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
Ch. 10.4 - Prob. 1GRCh. 10.4 - Prob. 2GRCh. 10.7 - Prob. 1EGCh. 10.7 - Prob. 2EGCh. 10 - A couple was referred for genetic counseling...Ch. 10 - A couple was referred for genetic counseling...Ch. 10 - A couple was referred for genetic counseling...Ch. 10 - Many individuals with metabolic diseases are...Ch. 10 - Prob. 2QPCh. 10 - Enzymes have all the following characteristics...
Ch. 10 - Questions 4 through 6 refer to the following...Ch. 10 - Questions 4 through 6 refer to the following...Ch. 10 - Prob. 6QPCh. 10 - Prob. 7QPCh. 10 - Prob. 8QPCh. 10 - a. Compounds A, B, C, and D are known to be...Ch. 10 - b. Compounds A, B, C, and D are known to be...Ch. 10 - a. If an individual who is homozygous for the...Ch. 10 - Prob. 12QPCh. 10 - Suppose that in the formation of phenylalanine...Ch. 10 - If phenylalanine was not an essential amino acid,...Ch. 10 - Phenylketonuria and alkaptonuria are both...Ch. 10 - The normal enzyme required for converting sugars...Ch. 10 - Knowing that individuals who are homozygous for...Ch. 10 - Prob. 18QPCh. 10 - A person was found to have very low levels of...Ch. 10 - If an extra nucleotide is inserted in the first...Ch. 10 - Transcriptional regulators are proteins that bind...Ch. 10 - Prob. 22QPCh. 10 - Prob. 23QP
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