Question

A hypothetical population of 200 cats has two alleles, T^L and T^S, for a locus that codes for tail length. The table below describes the phenotypes of cats with each possible genotype, as well as the number of individuals in the population with each genotype. Which statements about the population are true?

 

Genotype	Phenotype (tail length)	Number of individuals in population
TLTL	long	60
TLTS	medium	40
TSTS	short	100

Select all that apply.

Assuming random mating, each gamete has a \(40 \%\) chance of having a \(T^{L}\) allele and a \(60 \%\) chance of having a \(T^{S}\) allele.

 

Assuming random mating, each gamete has a \(50 \%\) chance of having a \(T^{L}\) allele and a \(50 \%\) chance of having a \(T^{S}\) allele.

Homozygotesmake up \(30 \%\) of the population.

In the entire cat population, \(60 \%\) of the alleles are \(T^{S}\).

In the entire cat population, the frequency of the \(T^{S}\) allele is 0.5.

In the entire cat population, the frequency of the \(T^{L}\) allele is 0.4

In the entire cat population, \(50 \%\) of the alleles are \(T^{S}\).

Heterozygotes make up \(20 \%\) of thepopulation.

Heterozygotes make up \(70 \%\) of thepopulation.

Homozygotesmake up \(80 \%\) of the population.

 

Answer 1

The following is the information provided:

$$ \begin{array}{|l|l|} \hline \text { Genotype } & \begin{array}{l} \text { No. of } \\ \text { Individuals } \end{array} \\ \hline T^{\perp} T^{\mathcal{L}} & 60 \\ \hline T^{S} I^{S} & 100 \\ \hline T^{L} T^{5} & 40 \\ \hline \end{array} $$

Genotype frequency:

Long tail (homozygous long) \(=\frac{60}{200}=0.3(30 \%)\)

Short tail (homozygous short) \(=\frac{100}{200}=0.5(50 \%)\)

Medium tail (heterozygous) \(=\frac{40}{200}=0.2(20 \%)\)

Allele frequency:

Dominant allele \(=\frac{120+40}{400}=\frac{160}{400}=0.4\)

Recessive allele \(=\frac{200+40}{400}=\frac{240}{400}=0.6\)

From the genotype and allele frequencies, we can see that the following statements are true:

- Assuming random mating, each gamete has \(40 \%\) chance of having \(\mathrm{T}^{\mathrm{L}}\) allele and \(60 \%\) chance of having a \(\mathrm{T}^{5}\) allele

- In the entire cat population, \(60 \%\) of the alleles are \(\mathrm{T}^{\text {S }}\)

- In the entire cat population, the frequency of \(\mathrm{TL}\) allele is 0.4. Heterozygotes make up \(20 \%\) of the population

- Homozygotes make up \(80 \%\) of the population