Campbell Biology: Concepts & Connections (8th Edition)
8th Edition
ISBN: 9780321885326
Author: Jane B. Reece, Martha R. Taylor, Eric J. Simon, Jean L. Dickey, Kelly A. Hogan
Publisher: PEARSON
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Chapter 13, Problem 12TYK
Sickle-cell disease is caused by a recessive allele. Roughly one out of every 400 African Americans (0.25%) is afflicted with sickle-cell disease. Use the Hardy-Weinberg equation to calculate the percentage of African Americans who are carriers of the sickle-cell allele. (Hint: q2 = 0.0025 .)
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While studying the frequency of sickle-cell disease ("sickle cell anemia") in a population living in sub-Saharan Africa, you obtain the following data from a sample of n= 100 people (note that I chose a simpler system for identifying the alleles rather than using "Hb S" for sickle cell allele), which is the actual name and what you used in lab). What is the frequency of the sickle cell allele (b) in the sample below from a human population?
Sample Data
BB-60 individuals (No sickle cell disease)
Bb-30 individuals (No sickle cell disease)
bb-10 individuals (Sickle cell disease)
1. 0.25
2. 0.10
3. 0.35
4. 0.60
5. 0.20
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.
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Maple Syrup Urine Disease (MSUD) is an autosomal recessive condition that causes intellectual and physical disabilities, difficulty feeding, and a sweet maple syrup odor to the urine. In Costa Rica, the incidence of MSUD is calculated as approximately 1 in 8,000 newborns. Calculate the allele frequencies for the normal and disease alleles.
Chapter 13 Solutions
Campbell Biology: Concepts & Connections (8th Edition)
Ch. 13 - Summarize the key points of Darwins theory of...Ch. 13 - Complete this concept map describing potential...Ch. 13 - Which of the following did not influence Darwin as...Ch. 13 - Natural selection is sometimes described as...Ch. 13 - In an area of erratic rainfall, a biologist found...Ch. 13 - If an allele is recessive and lethal in...Ch. 13 - In a population with two alleles, B and b, the...Ch. 13 - Within a few weeks of treatment with the drug 3TC,...Ch. 13 - Prob. 9TYKCh. 13 - Write a paragraph briefly describing the kinds of...
Ch. 13 - In the early 1800s, French naturalist Jean...Ch. 13 - Sickle-cell disease is caused by a recessive...Ch. 13 - It seems logical that natural selection would work...Ch. 13 - SCIENTIFIC THINKING Cetaceans are fully aquatic...Ch. 13 - A population of snails is preyed on by birds that...Ch. 13 - Advocates of scientific creationism and...
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- In the genetics unit you learned that sickle cell anemia is an autosomal recessive condition. In 2016, assume in the City of Markham there are 1000 people out of 300000 people who have sickle cell anemia. Assume global warming continues for the next 50 years and in the year 2066 there are 20000 people out of 500000 in Markham who have sickle cell anemia. a)What are the allele frequencies in 2016? What are the allele frequencies in 2066? Is microevolution evident? b)Due to global warming, assume the numbers of malaria carrying mosquitoes in Markham dramatically increased between 2016 and 2066. What do you believe is the main cause of the microevolution in Markham? (Hint- refer to the 5 factors affecting microevolution and refer back…arrow_forwardSickle cell anemia is caused by a recessive allele at a single gene. As we discussed in class, being a homozygote for the sickle cell allele is almost always lethal, but heterozygotes tend to be resistant against malaria although they have a mild form of anemia. Because of this heterozygote advantage, the allele for sickle cell anemia has a frequency of more than 10% in some human populations. How would present allele frequencies of the sickle cell allele change, if there was no heterozygote advantage or disadvantage (that is, that heterozygotes would be identical to ‘normal’ homozygotes – no malaria resistance, no anemia)? How would the change in sickle cell allele frequencies compare to scenario a (extirpation of malaria)arrow_forwardA pedigree analysis was performed on the family of a man with schizophrenia. Based on the known concordance statistics, would his MZ twin be at high risk for the disease? Would the twins risk decrease if he were raised in an environment different from that of his schizophrenic brother?arrow_forward
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