in a large genetic cross, 50% of the offspring have dominant phenotype and?

Question

in a large genetic cross, 50% of the offspring have dominant phenotype and 50% have the recessive phenotype. What are the most probable genotypes of the parents used in this cross?

Answer 1

The genotypes of the parents are:

Dd (heterozygote), and dd (homozygote).

If you cross Dd and dd together, you'll get 50% dominant and 50% recessive offsprings.

Answer 2

Assuming this is a simple problem of dominance and such, first start by going through the ratios you know, keeping in mind that each parent must carry at lest one recessive gene to be able to have offspring with a recessive phenotype:

Parent Rr crossed with Rr gives 75% dominant phenotype and 25% recessive.

Parent Rr crossed with rr gives 50% dominant phenotype and 50% recessive

There you go! And if you don't understand where the percents came from, draw some punnet squares for the different crosses.

Answer 3

One heterozygote and one homozygote recessive type.