population is black in colour but about 1/4 of them are white. gene (B) that produces an enzyme that converts a pigment molecule to produce the Black colour. There are 2 alleles of this gene - the dominant B and the recessive b. DNA analysis shows that black individuals have either a BB or Bb genotype and that white individuals have a bb phenotype. However, you have discovered that a small percentage of White individuals have either a BB or Bb genotype. Explain two reasons that could explain this apparent anomaly. They have a BB or Bb genotype but a white phenotype.

population is black in colour but about 1/4 of them are white. gene (B) that produces an enzyme that converts a pigment molecule to produce the Black colour. There are 2 alleles of this gene - the dominant B and the recessive b. DNA analysis shows that black individuals have either a BB or Bb genotype and that white individuals have a bb phenotype. However, you have discovered that a small percentage of White individuals have either a BB or Bb genotype. Explain two reasons that could explain this apparent anomaly. They have a BB or Bb genotype but a white phenotype.

Concepts of Biology

1st Edition

ISBN:9781938168116

Author:Samantha Fowler, Rebecca Roush, James Wise

Publisher:Samantha Fowler, Rebecca Roush, James Wise

Chapter8: Patterns Of Inheritance

Section: Chapter Questions

Problem 13RQ: When a population has a gene with four alleles circulating, how many possible genotypes are there?...

See similar textbooks

Similar questions

In a certain population of mice, a single gene controls fur color. There are two possible alleles: B, which leads to a black fur, and W, which leads to white fur. Individuals with the genotype BB will have a black fur, individuals with the genotype WW will have white fur, and individuals with the genotype BW will have gray fur. Scientists recorded the fur color of 1,000 mice from the population. They found that 200 mice have black fur, 400 have gray fur, and 400 have white fur. Ten years later, the measurements are repeated. Again, they recorded the fur color of 1,000 mice. They found that 400 have black fur, 400 have gray fur, and 200 have white fur. Part A: Show the Hardy-Weinberg calculations for the beginning and ending populations. Include the values for the equation as well as the p and q values. Show your work. Part B: Use the Hardy-Weinberg calculation to explain if this population is evolving or not. Then propose a hypothesis about the environment of these mice that would lead…
A mountain region has a population of 5,000 mountain goats. You score these animals for the R locus and find that this locus has two alleles, R (dominant) and r (recessive). 3200 individuals are homozygous dominant, 1,600 are heterozygous, and 200 are homozygous recessive. A deadly virus infects all of the RR mountain goats in the population (above), killing all individuals of this genotype and leaving the population with only the rr and Rr mountain goats. a) Calculate the new allele frequencies for this population. Show your work. b) Calculate the new (observed) genotypic frequencies for this population. Show your work. c) Does this population still appear to be at H-W equilibrium? Why or why not? (You do not need to analyze this statistically).
The eugenic movement was created in the early 20th century by Sir Francis Galton. Its aim was to improve the genetic pool of the human population by selective breeding. One idea was to discourage individuals with Mendelian autosomal recessive diseases to have children. However, the fallacy of this idea is shown by the fact that recessive lethal alleles (that are never found in homozygosity) can persist in populations for hundreds to thousands of generations. Which one of the following statements best explains the persistence of those alleles in populations? There is heterozygote advantage in those populations. Recessive alleles keep being produced by mutation. Recessive alleles cannot be selected against when present in heterozygotes. Genetic drift keeps recessive alleles at a relative high frequency in populations. Consider the action of mutation and of genetic drift in a population. What do you expect genetic variation will be in a…
A given autosomal locus has three possible alleles (A1, A2, and A3). Assuming that the numbers of individuals with the six possible genotypes are as follows, what would be the frequency of the A1 allele in the population? A1A1 = 30 A1A2 = 27 A2A2 = 12 A1A3 = 17 A2A3 = 10 A3A3 = 4 What is the frequency of A1 allele in the population? A. 0.375 B. 0.52 C. 0.305 D. 0.175 E. 0.74
A genetic mutation that causes deafness in humans has an autosomal recessive pattern of inheritance. In a study of a population of 235 Turkish children, 48 displayed the recessive phenotype. The frequency of the heterozygous genotype in the population of Turkish children described above is?
Albinism in humans is a relatively rare recessive condition. Let the allele for normal pigmentation be A and the allele for albinism be a. Therefore, individuals with the genotypes AA and Aa are normally pigmented individuals and aa are albinos. Suppose that in the US the frequency of albinos is 1 in 10,000. Estimate the allele frequencies and the frequencies of AA, Aa and aa genotypes in the population. Show all your work, and clearly state your logic and any assumptions you make in estimating the frequencies.
A form of learning disabilities and speech impairment results from a recessive mutation in the HERC2 gene. The next 4 questions are about this mutation. In a small Amish village in Ohio, about 5 per 1000 births are affected with this disorder. Assume Hardy Weinberg equilibrium. What is the frequency of the dominant WT HERC2 allele in this small village? A form of learning disabilities and speech impairment results from a recessive mutation in the HERC2 gene. The next 4 questions are about this mutation. Part a: In a small Amish village in Ohio, about 5 per 1000 births are affected with this disorder. Assume Hardy Weinberg equilibrium. What is the frequency of the dominant WT HERC2 allele in this small village? a)0.005 b)0.995 c)0.07 d)0.93 Part b: What is the estimated total number of homozygous dominant individuals in this village of 1000 people? a) 70 b) 930 c) 860 d) 140
Since DNA sequences are passed down from one generation to the next, people with closer familial relationship tend to have more of their DNA sequences in common. As a result, people who are more genetically related tend to share some similar patterns in their DNA fingerprinting. If you are comparing samples, which of the following can be determined with DNA fingerprinting? Group of answer choices? right chances Which fraternal twin each sample came from Which identical twin each sample is from If the samples are from people who are married If the samples came from mother and child asap please
If the frequency of those exhibiting a monogenic autosomal recessive phenotype caused by a rare clinically relevant allele is 1/8500 in a given population, what is the carrier frequency? Please give your answer as a percentage to 3 decimal places, do not include the % symbol. ANSWER: In a population where the frequency of those exhibiting a monogenic autosomal recessive phenotype caused by only one known mutation is 1/8500 the carrier frequency is a percent.
Sickle 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)
The frequency of an autosomal recessive condition is 0.001 (1 in 1000) in a population. What is the frequency of the mutant allele? Express your answers using three significant figures.
A mutation produces a new beneficial dominant allele. Which of the following statements is false when considering the rate of frequency change that will be observed for this allele in the population? a) The allele will initially be present in heterozygotes. b) It is less likely to reach frequency of 1.0 than if it had been recessive. c) Its frequency will increase slowly until homozygotes occur in the population. d) Individuals with this allele will express the favorable phenotype.