This quiz will cover the notes we took in class and dihybrid punnett squares we have practiced. Make sure you understand how to do these punnett squares. If you are confused please come in for tutoring.
Dihybrid cross notes
Law of Independent Assortment:
The two alleles that control a trait separate during the formation of gametes (egg/sperm cells).
In other words one of the gametes get one allele and the other gamete gets the other allele.
Alleles for different traits can be inherited independently (random) from each other during formation of egg/sperm cells when they are on different chromosomes.
Exceptions: Dihybrid crosses
How to complete a dihybrid cross punnett square:
Use the “FOIL” method
Parent genotype: RrBb
Possible gametes: RB, Rb, rB, rb
**When two parents are crossed in dihybrid crosses if they are heterozygous for both traits the phenotypic ratio will always be 9:3:3:1.