Human Biology Custom Edition
11th Edition
ISBN: 9781337631532
Author: Cecie Starr, Beverly McMillan
Publisher: Cengage Learning
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Chapter 20, Problem 6CT
About 4 percent of people of Northern European descent have a cystic fibrosis allele, but only about 1 in 2,500 of these people actually has the disorder. What is the most likely reason for this finding?
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Chapter 20 Solutions
Human Biology Custom Edition
Ch. 20 - Prob. 1RQCh. 20 - What is a carrier of a genetic trait?Ch. 20 - What evidence indicates that a trait is coded by a...Ch. 20 - Prob. 4RQCh. 20 - Explain what nondisjunction is, and give two...Ch. 20 - _______ segregate during ______. a. Homologues;...Ch. 20 - Prob. 2SQCh. 20 - Genes on the same chromosome tend to stay together...Ch. 20 - Prob. 4SQCh. 20 - A chromosomes structure can be altered by _______....
Ch. 20 - Nondisjunction can be caused by ________. a....Ch. 20 - A gamete affected by nondisjunction could have...Ch. 20 - Genetic disorders can be caused by __________. a....Ch. 20 - A person who is a carrier for a genetic trait...Ch. 20 - Prob. 10SQCh. 20 - If a couple has six boys, what is the probability...Ch. 20 - Human sex chromosomes are XX for females and XY...Ch. 20 - People with Down syndrome have an extra copy of...Ch. 20 - Prob. 4CTCh. 20 - Prob. 5CTCh. 20 - About 4 percent of people of Northern European...Ch. 20 - The following pedigree shows the pattern of...
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- Cystic fibrosis is an autosomal recessive disorder that affects 1 in 3 000 newborns with Caucasian background. It causes thick mucus build up in various organs and can cause damages and problems in respiratory and digestive systems. a) What is the frequency of the cystic fibrosis allele in the Caucasian population? Show all your work and express your answer as a value between 0 and 1 rounded to two decimal places. b) What percentage of the Caucasian population would be carriers for cystic fibrosis? Show all your work and express your answer rounded to two decimal places. c)If two individuals are carriers of the cystic fibrosis allele, what is the probability that they would have a girl without cystic fibrosis? Show all your work (including the Punnett square) and express your answer as a value between 0 and 1 rounded to two decimal places.arrow_forwardIdentify each of the following as an example of allele, genotype, and/or phenotype frequency: A. Approximately 1 in 2500 people of Northern European descent is born with cystic fibrosis. B. The percentage of carriers of the sickle cell allele in West Africa is approximately 13%. C. The number of new mutations for achondroplasia, a genetic disorder, is approximately 5 × 10–5.arrow_forwardSuppose we define the Alzheimer's disease phenotype as being diagnosed with the disease by age 75 years. In the human population, there are three alleles of the ApoE gene: e2, e3, e4. They form an allelic series such that: 70% of 75 year olds with the e4/e4 genotype have the Alzheimer's phenotype 60% of 75 year olds with the e3/e4 genotype have the Alzheimer's phenotype 40% of 75 year olds with the e3/e3 genotype have the Alzheimer's phenotype 30% of 75 year olds with the e2/e4 genotype have the Alzheimer's phenotype 10% of 75 year olds with the e2/e3 genotype have the Alzheimer's phenotype If I have the e4/e4 genotype and my wife has the e2/e3 genotype, what is the probability that our child will have Alzheimer's by age 75. Explain your reasoning.arrow_forward
- What is heterozygote advantage. How does this phenomenon explain the preponderance of disorders such as cystic fibrosis and sickle cell anemia ?arrow_forward1. What are the symptoms of sickle cell disease (anemia)? 2. What is the genotype of sickle cell disease? Use these sources to find the answers: https://ghr.nlm.nih.gov/condition/sickle-cell-disease#inheritance https://www.cdc.gov/ncbddd/sicklecell/traits.htmlarrow_forwardThe allele of the gene responsible for the lung disorder, cystic fibrosis rose to prominence in Europe in the 1800s. Cystic fibrosis disease results from thick mucus accumulating in the lungs, which occurs in individuals who are homozygous for the CF allele. A pleiotropic effect is that heterozygous individuals are less likely to suffer from diarrhea. During the European cholera epidemics of the 1800s, resistance against diarrhea conferred a survival advantage such that approximately one in every 400 people in some European populations have cystic fibrosis. Fill in the table below with the genotype and allele frequencies for this 1 in 400 occurrence and provide the Hardy-Weinberg principle model you will be using. (Assume that individuals with the cystic fibrosis trait (CF) reproduce normally and that good sanitation means that there is currently no fitness advantage to diarrhea resistance.) phenotype CF DR normal (totals) Genotype cc Cc CC Number of Individuals 1 ______…arrow_forward
- What would happen to the frequency of heterozygous carriers of sickle-cell anemia (with AS genotype) if mosquitoes were completely wiped out in a large region?arrow_forwardWhat is the frequency of sickle cell disease (anemia)? https://ghr.nlm.nih.gov/condition/sickle-cell-disease#inheritance https://www.cdc.gov/ncbddd/sicklecell/traits.htmlarrow_forwardSuppose we define the Alzheimer’s disease phenotype as being diagnosed with the disease by age 75 years. In the human population, there are three alleles of the ApoE gene: ε2, ε3, ε4. They form an allelic series such that: 70% of 75 year olds with the ε4/ ε4 genotype have the Alzheimer’s phenotype 60% of 75 year olds with the ε3/ ε4 genotype have the Alzheimer’s phenotype 40% of 75 year olds with the ε3/ ε3 genotype have the Alzheimer’s phenotype 30% of 75 year olds with the ε2/ ε4 genotype have the Alzheimer’s phenotype 10% of 75 year olds with the ε2/ ε3 genotype have the Alzheimer’s phenotype If I have the ε4/ ε4 genotype and my wife has the ε2/ ε3 genotype, what is the probability that our child will have Alzheimer’s by age 75. Explain your reasoning. [Can be answered in less than 75 words]arrow_forward
- While sitting at home during Movement Control Order (MCO) because of pandemic covid19, observe two different traits of a couple in your family (eg. your mom & dad or your sister & her husband or your brother & his wife, etc). Draw a genetic cross that involves cross of the parents with the chosen 2 pairs of their contracting traits. Imagine that the cross obeys the Mendelian Laws, show the cross and gametes production for each generation (P, F1 and F2). By Using a Punnet square as symbolic representation of the results for the cross, determine the phenotypes, genotypes, phenotypic ratio and genotypic ratio of F2 generation in the family.arrow_forwardCystic fibrosis in humans is caused by a recessive allele. A man is known to be a carrier of the cystic fibrosis allele. He marries a phenotypically normal woman. In the general population, the incidence of cystic fibrosis at birth is approximately 1 in 1,700. Assume Hardy-Weinberg proportions. What is the probability that the wife is also a carrier? Answer in decimal number only (three decimal places; example: 0.123). What is the probability that their first child will be affected? Answer in decimal number only (three decimal places; example: 0.123).arrow_forwardIdentify each of the following as an example of allele, genotype,and/or phenotype frequency:A. Approximately 1 in 2500 individuals of Northern Europeandescent is born with cystic fibrosis.B. The percentage of carriers of the sickle cell allele in WestAfrica is approximately 13%.C. The number of new mutations per generation resultingin achondroplasia, a genetic disorder, is approximately5 × 10−5.arrow_forward
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