Punnett Squares and Genetic Predictions

Question 1

What is a Punnett square?

Answer 1

A diagram used to predict the probabilities of genotypes and phenotypes in offspring.

Question 2

What is the probability of getting a heterozygous offspring from a cross between Aa and Aa?

Answer 2

50% heterozygous (Aa).

Question 3

If a monohybrid cross has a dominant allele (A) and recessive allele (a), what is the phenotypic ratio?

Answer 3

3:1 (dominant).

Question 4

In a dihybrid cross (AaBb x AaBb), what is the phenotypic ratio?

Answer 4

9:3:3:1 for two traits (dominant-dominant, dominant-recessive, recessive-dominant, recessive-recessive).

Question 5

How can you identify linked genes from dihybrid cross results?

Answer 5

If parental phenotypes are overrepresented compared to recombinant phenotypes, the genes are likely linked.