Question

unit exam - genetics
how many possible outcomes are there in a dihybrid cross?
2
16
4

Explanation:

Step1: Understand dihybrid cross

A dihybrid cross involves two pairs of contrasting traits.

Step2: Use formula for number of gametes

For each trait, if the genotype is heterozygous (e.g., \(Aa\)), the number of gametes per trait is \(2\). For two traits (\(AaBb\)), the number of gametes is \(2\times2 = 4\) (gametes: \(AB\), \(Ab\), \(aB\), \(ab\)).

Step3: Calculate number of offspring

Using Punnett square method, when two individuals with \(4\) gametes each are crossed, the number of possible offspring is \(4\times4=16\).

Answer:

16