Genetics mixed review problems
Name ​i’m not sure this is hard sorry
Directions: Find the parental genotypes. Complete the Punnett square. Determine the genotype and phenotype ratios of
the offspring.
1. Simple Dominance:
-Cross a heterozygous red flower with a white flower. Red is dominant over white.
Parent Genotypes: ​Rr​ x ​rr
Rr
rr
Rr
rr
Genotype Ratio: 50% Rr | 50% rr
Phenotype Ratio: 50% Red | 50% White
2. Incomplete Dominance:
-When an offspring receives one red allele and one white allele, the result is a pink phenotype. Cross a red flower with a
white flower.
Parent Genotypes: ​RR​ x ​rr
Rr
Rr
Rr
Rr
Genotype Ratio: 100% Rr
Phenotype Ratio: 100% Pink
3. Co-dominance:
-When an offspring receives one red allele and one white allele, the result is a flower with red and white pedals. Cross a
red flower with a white flower.
Parent Genotypes: ​RR​ x ​rr
Rr
Rr
Rr
Rr
Genotype ratio: 100% Rr
Phenotype ratio: 100% Pedals
4. Blood type:
-Cross a woman with blood type A blood that is heterozygous for the trait with a man with blood type O.
Parent Genotypes: ​B(A)B(O)​ x ​B(O)B(O)
B(A)B(O)
B(O)B(O)
B(A)B(O)
B(O)B(O)
Genotype ratio: 50% B(A)B(O) | 50% B(O)B(O)
Phenotype ratio: 50% Type A | 50% Type O
5. X-linked:
-Colorblindness is an x-linked recessive trait. Cross a woman who is a carrier of the colorblind allele, with a man who has
normal vision.
Parent Genotypes: ​X(C)X(c)​ x ​X(C)Y
X(C)X(C)
X(C)Y
X(C)X(c)
X(c)Y
Genotype ratio: 25% X(C)X(C) | 25% X(C)X(c) | 25% X(C)Y | 25% X(c)Y
Phenotype ratio: 25% Female, Normal | 25% Female, Carrier | 25% Male, Normal | 25% Male, Colorblind
6. Define:
Homozygous: Both alleles are the same
Heterozygous: Both alleles are different
Dominant: Overpowers recessive
Recessive: Gets overpowered by dominant
Allele: Half of a genotype
Genotype: Both alleles
Phenotype: What you can see