In cats, having a short tail is recessive to having a long tail. If a mother cat is heterozygous for this trait and a father cat is homozygous dominant for having a long tail, what will most likely be true about their offspring?

A. All will have long tails.
B. All will have short tails.
C. About [tex]$\frac{3}{4}$[/tex] will have short tails.
D. About [tex]$\frac{1}{2}$[/tex] will have long tails.



Answer :

Sure! Let's break down the given scenario and determine the outcome for the offspring.

In genetics, traits are determined by alleles, which can be dominant or recessive. Here, the trait in question is tail length in cats. Having a long tail (L) is dominant over having a short tail (l).

The mother cat is heterozygous for the tail length trait, meaning she has one dominant allele (L) and one recessive allele (l). Therefore, her genotype is [tex]\( Ll \)[/tex].

The father cat is homozygous dominant, meaning he has two dominant alleles (L). Therefore, his genotype is [tex]\( LL \)[/tex].

When these cats reproduce, the possible combinations of their alleles can be determined using a Punnett square. Let's create one to visualize all possible combinations of the offspring's alleles.

| | Father L | Father L |
|----------|----------|----------|
| Mother L | LL | LL |
| Mother l | Ll | Ll |

From the Punnett square, we can observe:
1. The offspring genotype produced by combining an L from the mother and an L from the father is [tex]\( LL \)[/tex], resulting in a long tail.
2. The offspring genotype produced by combining an l from the mother and an L from the father is [tex]\( Ll \)[/tex], also resulting in a long tail since L is dominant over l.

Therefore, the possible genotypes of the offspring are:
- [tex]\( LL \)[/tex] – long tail
- [tex]\( Ll \)[/tex] – long tail

In this scenario, because the L allele is dominant, all possible genotype combinations (LL and Ll) result in offspring with long tails. As such, 100% of the offspring will have long tails.

The correct answer is: All will have long tails.