Predicting Outcomes of Genetic Crosses
• Phenotype:
– The physical trait that is
expressed in the organism.
– Ex: Blue or Brown Eyes
• Genotype:
– The combination of alleles How could you determine if
in an organism.
an organism is homozygous
or heterozygous for brown
– Ex: BB, Bb, or bb
eyes? (Testcross)
Predicting Outcomes of Genetic Crosses
• Punnett square: diagram to predict the genotype and
phenotype ratios of genetic crosses.
Make a Punnett square to
show Mendel’s P
generation where he
crossed a homozygous tall
plant with homozygous
short plant.
Make a Punnett square to
show Mendel’s F1 cross
with two heterozygous tall
plants.