Question

If a population is made up of 30 AA individuals, 50 Aa individuals, and 20 aa individuals, what is the frequency of the A allele? 0.35 0.4 0.55 0.8

Answer 1

9) This problem is based on Hardy-Weinberg equilibrium.

Calculating allelic frequencies by

counting up the alleles and dividing by the total number of alleles in the population

In the question it is given that the population is made up of 30AAs ,50Aas and 20aas

therefore the allelic frequency of A allele is calculated by{ (30*2)+50}/{(30+50+20)*2}=110/200

=0.55(option c is correct)

explanation

Number of dominant A alleles in 30 people are 60.There are 60 dominant alleles in these 30 homozygotic dominant people.Because each one of these people carrying 2 dominant alleles.

Dominant alleles in 50 heterozygote is 50.Each one of these heterozygotic individual carrying only one dominant A allele.

There are no dominant allele in 20 aas.These individuals are homozygous recessive.

The denominator in the answer is total number of alleles not individuals.Total number of people is 100.Each individual carries 2 alleles.Hence 200.

We can also calculate frequency of a allele by this method

frequency of a allele={(20*2)+50}/(100*2)

=90/200=0.45

According to Hardy-Weinberg equilibrium p+q=1(here A and a)

.55+.45=1

10)Option D is the correct answer.

Sexual reproduction occur when male and female gamete fuse together.Half of the offspring chromosome come from mother and other half from father.Offspring are genetically different from parents as well as from siblings.Independent assortment of chromosome during meiosis and random fertilization adds variation and possibility of adaptation to environment.

In asexual reproduction there is no mixing of genetic materials.A single individual is capable of producing offspring,As a result offspring that are produced are not only identical to one another but are also exact copies of their parent.The term clone is used to describe such individuals.

Option A is incorrect.Asexual species reproduce faster than sexual species.Muller"s ratchet is a process that result in accumulation of harmful mutations due to the absence of recombination.It occur in asexual reproduction.

Option B is incorrect.Asexual species exhibit a faster mutation rate.

Option C is incorrect.Sexual eukaryotic species tend to be longer lived and to speciate more than asexual species.Because sexual reproduction creates variation and the species can adapt to new environment due to this variation.More over a disease is less likely to affect all the individuals in the population.In asexual reproduction there is no variation and the organism may only be suited to one habitat.Chances of affecting a disease to all individual is high.Sexual reproduction permits random mating.random mating result in blending of characters.