1>>in a large, randomly mating herd of cattle, 16 percent of the newborn calves

Question

1>>in a large, randomly mating herd of cattle, 16 percent of the newborn calves have a certain type of dwarfism due to a homozygous recessive allele. Assume the population is in Hardy~Weinberg equilibrium.

a>What is the frequency of the recessive dwarfing allele?

b> what is the frequency of the normal allele?

c> what proportion of the normal cattle are homozygous?

d> what is the frequency of the individuals with dwarfism?

e> what is the frequency of carriers in the population?

2>>Phenylketonuria (PKU) is a recessive genetic disorder in metabolism that can lead to mental retardation and other health problems. Approximately 1 in 10000 babies are born with this disease.
a> What is the frequency of the PKU allele?
b> what proportion of the population are PKU carriers?

Explanation / Answer

1). 16 percent of the newborn calves have a certain type of dwarfism due to a homozygous recessive allele

q^2 = 16% = 0.16

q = 0.4

a> the frequency of the recessive dwarfing allele q = 0.4

b> the frequency of the normal allele p= 1-0.4=0.6

c> proportion of the normal cattle are homozygous = PP = 0.6 *0.6 = 0.36

d> the frequency of the individuals with dwarfism = qq = 0.4 * 0.4 = 0.16

e> the frequency of carriers in the population = 2pq = 2 * 0.6 * 0.4 = 0.48

2). percentage of population having phenylketonuria = 1/ 10000 = 0.0001

q^2= 0.0001

a> the frequency of the PKU allele = q = 0.01

p = 1-0.01 = 0.99

p^2 = 0.99 * 0.99 = 0.9801

b> proportion of the population are PKU carriers = 2pq = 2 * 0.99 * 0.01 = 0.0198

Number of people that are carriers are 0.0198 * 10000 = 198

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.