Holsteins being black and white is dominant over being red and white what what are the chances of a homozygous dominant for a heterozygous cow having a calf that is red

25 % chance of homozygous dominant of white calf that is red.

Explanation:

dominant traits = black and white BBWW

recessive trait = red and white  bbWw

cross between the heterozygous cows

        bW      bw

bW  bbWW bbWw

bw  bbWw  bbww

There will be 25 % chance of homozygous dominant of white calf that is red also.

when two calves that are white and red and heterozygous for the red and white trait mated they produce a phenotype ratio of 3:1 and genotype ratio of 1:2:1. Out of total progeny in punnet square 75% are red and white calves while 25% are red and but no white colour on the skin.

It shows one of the allele in white gene is recessive trait.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.