Understanding Genotypes and Alleles in Cattle Breeding

What are the most likely genotypes of the parents?

A. SS and ss
B. Ss and ss
C. SS and Ss
D. Ss and Ss

Why is C the wrong answer and which one is the correct answer?

The answer would be D because you inherit traits from both parents.

In cattle breeding, the allele for short horns (S) is dominant over the allele for long horns (s). When two short horn cows are bred and produce four offspring, where three have short horns and one has long horns, we can deduce the genotypes of the parents based on the principle of inheritance.

In this scenario, since short horns are dominant, the offspring with long horns (ss) must have inherited the recessive allele from both parents. Therefore, the correct genotypes of the parents would be Ss and Ss. This combination allows for the possibility of both short horn offspring (SS) and long horn offspring (ss), as observed in the four offspring produced.

The reason why option C (SS and Ss) is the wrong answer is because if one of the parents carried the genotype SS, there would not have been any long horn offspring (ss) produced. This is because the dominant allele (S) would always override the recessive allele (s) in the offspring's genotype.