13. Mendelian Genetics

Assume that there is a gene in apples that determines fruit color and a second gene that determines fruit size. Let A represent the dominant allele for big apples and a represent the recessive allele for small apples. Similarly, let R represent the dominant allele for red apples and r represent the recessive allele for yellow apples. You have one tree that produces big yellow apples and another tree that produces small red apples. When the two are crossed, you find that half of the new trees produce big red apples and half produce big yellow apples. What are the genotypes of the parents?

What is the name for a cross that examines the inheritance of two traits?

In a dihybrid cross, what is the expected phenotypic ratio of the offspring when both parents are heterozygous for two traits?