A test cross with an organism with a homozygous recessive genotype
results in 50% of the offspring exhibiting the recessive trait.
What is the genotype of the test-cross
parent?
I. Homozygous recessive
II. Homozygous dominant
III. Heterozygous
A. I only
B. II only
C. III only
D. I or III
E. II or III