Question

in hereford cattle, one gene determines whether or not a cow will have horns. the allele that produces horns is recessive (h), and the allele that results in no horns is dominant (h). if two heterozygous cows mate, what are the predicted phenotypes of their offspring? 0% horns, 100% no horns 25% horns, 75% no horns 75% horns, 25% no horns 100% horns, 0% no horns

Explanation:

Step1: Determine the genotypes of parents

Heterozygous cows have the genotype \(Hh\).

Step2: Set up Punnett square

	\(H\)	\(h\)
\(h\)	\(Hh\)	\(hh\)

Step3: Analyze phenotypes

• \(HH\) and \(Hh\) (dominant allele \(H\) present) → no horns.
• \(hh\) (recessive alleles) → horns.
• \(HH: Hh: hh = 1:2:1\).
• Proportion of no - horns (\(HH + Hh\)): \(\frac{1 + 2}{4}=\frac{3}{4}=75\%\).
• Proportion of horns (\(hh\)): \(\frac{1}{4} = 25\%\).

Answer:

25% horns, 75% no horns