If all the offspring of a testcross are alike and resemble the organism being tested, then that parent is ____.
A)homozygous dominant
B)homozygous recessive
C)heterozygous
D)recessive
E)incompletely dominant

Question

Quizplus · Accepted Answer

In a testcross, an organism (whose genotype we want to determine) is crossed with a homozygous recessive individual. If all offspring resemble the tested parent, it indicates that the parent must be homozygous dominant, as only dominant alleles are present to be passed on, ensuring all offspring display the dominant phenotype.

If All the Offspring of a Testcross Are Alike and Resemble