The brown fur trait in a bear species is recessive. You find a bear population where 1 in 625 is brown. How many bears in this population are heterozygous if the population is at Hardy-Weinberg equilibrium?
A.600
B.300
C.100
D.48
E.25
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The following questions are based on information in the Ritland & Marshall (2001) abstract (see OA2 folder). Choose the best answer for each question.
What is the frequency of heterozygotes if the population is under Hardy Weinberg equilibrium?
How many bears are expected to be heterozygotes given the population is at Hardy Weinberg equilibrium?
What is the frequency of the Cys/ Cys genotype?
What is the frequency of the black bear genotype Tyr / Tyr if the population is at Hardy Weinberg equilibrium?
What is the frequency of the Cys allele?
https://www.ncbi.nlm.nih.gov/pubmed/11566108?dopt=Abstract this is the link for the abstract
0.438
96
0.1
0.46
0.32
Question 3 (8 points)
Brown fur stripes (autosomal recessive) is found in 13% of thesquirrels in Yellowstone National Park. Black is the dominantstripe color. Answer the following questions about this population,assuming this population of squirrels is in Hardy-Weinbergequilibrium with respect to fur stripes.
What are the frequencies of the brown stripe (b) and blackstripe (B) alleles?
â¨b) What is thefrequency of heterozygotes?
â¨c) In the nextgeneration, what is the proportion of heterozygote matings?(Hint: You will need to use the product rule.)
d) In the next generation, what proportion ofsquirrels will be brown stripe progeny resulting from heterozygotematings? (Hint: You will need to use the productrule.)
1. If an individual has a genotype of Bb, what types of gametes (sperm/egg) could they produce? A) B B) b C) B or b D) Bb, BB, bb E) Bb
2. Which of the following statements is true about phenotypic plasticity, i.e., phenotype variation that is the result of genotype by environment interactions? A. Phenotypic plasticity is only favored when the parental environment is a good predictor of the offspring environment B. Since the trait expression of a genotype varies across environments, it cannot respond to selection C. A variable environment is required for phenotypic plasticity to be selected for D. A single trait can only ever be plastic or non-plastic within a species E. Phenotypic plasticity can only occur within a single generation, never across generations
3. With large numbers of genes contributing to variation for a phenotypic trait (e.g. height in humans), the population approaches what kind of distribution for that trait? A. Mendelian B. Exponential C. Binomial D. Normal E. Continuous
4. A classic example of phenotypic plasticity is caste determination in social insects. Whether a female ant becomes a worker, soldier, or queen is determined by the food she is fed. Would you say this this an example of G, E, or GxE?
5. In an infinite population, the frequency of the A allele is 0.3 and the frequency of the a allele is 0.7. What is the frequency of heterozygotes? A. .10 B. .21 C. .30 D. .42 E. .70
6. Blue eyes are a recessive trait caused by an autosomal allele. If there are 180 people with blue eyes in a population of 500 people, what is the frequency of the brown-eye allele? (Assume HWE) A. .36 B. .40 C. .50 D. .60 E. .64
7. Imagine flower color in diploid roses is determined by a single gene with two alleles, white and red, which are co-dominant so that heterozygotes are pink. Frank is colorblind and can only discriminate between white and colored roses, and knows that his population has 18 white roses and 182 non-white roses. How many of Frankâs roses are pink? (Assume HWE.) A. 18 B. 21 C. 42 D. 84 âE. 100
8. Imagine flower color in diploid roses is determined by a single gene with two alleles, white and red, which are co-dominant. If Eva's population has 250 white roses, 500 pink roses, and 250 red roses, what is true about this population?
A. It is not in Hardy-Weinberg equilibrium B. It is under balancing selection C. It is connected to another population by migration D. It is in Hardy-Weinberg equilibrium ââE. White is a recessive lethal
9. 9% of a population is unable to taste the compound PTC, which is a recessive trait. Assuming HWE, if two carriers of the non-tasting allele had a baby what is the probability that it would be unable to taste PTC? A. 0.09 B. 0.25 C. 0.30 D. 0.50 E. 0.70
10. (Adapted from: Christensen, A. C. (2000). Cats as an aid to teaching genetics. Genetics, 155(3), 999-1004.) ss cats have no white fur, Ss cats generally have <50% white fur, and SS cats generally have >50% white fur (cats who are 100% white are scored as dominant white and can't be scored for piebald spotting). The S allele is incompletely dominant, but variably expressed, so there is a more-or-less continuous gradient of white pigmentation in populations. You and your friends score all non-white cats up for adoption: http://www.adoptapet.com/cat-adoption/search/50/miles/48824 and find there are 160 with >50% white fur, 350 with <50% white fur, and 490 with no white fur. Which of the following statements is definitely true:
A. The population is in Hardy-Weinberg equilibrium B. The population is not in Hardy-Weinberg equilibrium C. There is selection acting on the population D. It is impossible to know if the population is in Hardy-Weinberg equilibrium E. Fur color is not a heritable trait and therefore cannot evolve
