Among cattle, having horns is a recessive trait. cattle without horns, which are called polled cattle, are common. suppose a horned male mated with a polled female. their offspring are all polled. on maturity, two cattle of the f1 generation mated. their offspring are a mix of polled and horned cattle. in the f2 generation, is homozygous dominant and is homozygous recessive. a. pp b. pp c. pp

Option B, A

PP is the homozygous dominant pooled offsping

And pp is the homozygous recessive pooled offsping

Explanation:

Let the dominant trait "not having horn" being polled be represented by "P"

Let the recessive trait "having horns" be represented by "p"

As given in question male is horned and is crossed with a female that is polled so that all the offsprings are polled.

This would give the genotype of parents as -

Horned Male - pp

Polled Female -PP

Genotype of  polled offsprings in F1 generation - Pp

If two parents from F1 generation are crossed the the following offsprings would be produced

Pp X Pp

PP, Pp, Pp, pp

Thus, PP is the homozygous dominant pooled offsping

And pp is the homozygous recessive pooled offsping

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.