Question

If Individual 5 mates with a homozygous recessive horse, which of the following is a valid prediction about the offspring?


All of their offspring will be heterozygous dwarf horses.

Option A,All of their offspring will be heterozygous dwarf horses.

A

All of their offspring will be homozygous non-dwarf horses.

Option B,All of their offspring will be homozygous non-dwarf horses.

B

Half of their offspring will be heterozygous dwarf horses, and half of their offspring will be homozygous dwarf horses.

Option C,Half of their offspring will be heterozygous dwarf horses, and half of their offspring will be homozygous dwarf horses.

C

Half of their offspring will be homozygous recessive non-dwarf horses, and half of their offspring will be homozygous dominant dwarf horses

Answer 1

I can’t choose the correct option without knowing Individual 5’s genotype or the pedigree that defines it. However, here are the possible outcomes when you mate an unknown individual to a homozygous recessive tester (assume D = dwarf allele, d = non‑dwarf allele, with D dominant):

- If Individual 5 = DD (homozygous dominant): all offspring are Dd (heterozygous) and show the dwarf phenotype → matches Option A.
- If Individual 5 = Dd (heterozygous): offspring are 50% Dd (dwarf) and 50% dd (homozygous recessive, non‑dwarf) → matches none of the listed options exactly (closest would be "half dwarf, half non‑dwarf").
- If Individual 5 = dd (homozygous recessive): all offspring are dd (homozygous recessive, non‑dwarf) → matches Option B.

Options C and the last option are genetically impossible for a cross with a homozygous recessive mate.

If you post the pedigree or tell me what genotype/phenotype Individual 5 has, I’ll pick the correct option.