# Hardy-Weinberg Problems

```Hardy-Weinberg Problems
name___________________________hr__
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1. In a population of 100 individuals 49% are of the NN phenotype. What
percentage is expected to be Nn assuming Hardy-Weinberg equilibrium?
A. 9%
B. 21%
C. 42%
D. 51%
E. insufficient information to answer question
2. Attached ears is an autosomal recessive trait in humans. Assume that there are
400 people with attached ears in a population of 10,000. How many individuals
would be expected to homozygous dominant?
A. 800
B. 100
C. 6400
D. 200
E. 10,000
3. In a population that meets the H-W equilibrium assumptions, 81% of the
individuals are homozygous for a recessive gene. What percentage of the
individuals would be expected to be heterozygous for this gene?
4. A farmer bought a herd of 600 sheep, taken from a freely breeding population, and later
found that 150 of the animals had an economically undesirable feature, crinkly-hair, caused by
the recessive allele c. What is the frequency of this undesirable allele in the herd?
B.What proportion of the herd is likely to be heterozygous?
5. The alleles for red and white coat color in cattle show incomplete dominance, the
heterozygote being roan. In a freely breeding herd of 1000 head how many would you expect
to be of each coat color if the allele for white coat has a frequency of 0.4?
Hardy-Weinberg Problems
name___________________________hr__
6. In a sample of 2400 births at a maternity hospital, six babies died shortly after birth from
the effects of a recessive gene (c) for colonic obstruction.
A.What is the frequency of this gene in the population?
B.What proportion of the population is heterozygous and what proportion is homozygous for
the normal allele?
For the next three problems calculate the frequency of the three genotypes. Also calculate the
hypothesized actual number of the genotypes and the phenotypes.
7. A herd of 300 cows (+ a few bulls) with 12 homozygous recessive individuals.
8. A school(?) of 86 sea cows includes 24 individuals which have a recessive skin disorder
causing them to be fluorescent yellow.