Genetics Quiz: Blood Type Inheritance

Blood Type and Rh Factor Inheritance

• A heterozygous blood type B (B) individual with a heterozygous Rh-positive (Rh+) genotype will have the following alleles: B, b, R, r
• A homozygous blood type A (A) individual with a homozygous Rh-negative (Rh-) genotype will have the following alleles: A, A, r, r
• To determine the probability of their child having blood type A+ (A, A, R, r), consider the possible allele combinations:
  • Blood type A: The child must inherit at least one A allele from the mother
  • Rh-positive: The child must inherit at least one R allele from the father
• The possible allele combinations for the child are:
  • AR, Ar, bR, br
• Therefore, there is a 50% chance the child will have blood type A+ (A, A, R, r)

Flower Color Based on Pigmentation and pH

• The color of a flower is determined by the pigments it contains and the pH of the cell sap
• Anthocyanin pigments, when in an acidic cell sap (pH of 5 to 7), will produce red flowers.

Inheritance of Deaf-Mutism

• A deaf-mute man (BBtt) has a homozygous recessive genotype for both deafness (bb) and mutism (tt).
• His deaf-mute wife (bbTT) also has a homozygous recessive genotype for deafness (bb) and a homozygous dominant genotype for mutism (TT).
• The possible genotypes for their children are: BbTt, BbTt, BbTt, BbTt
• All their offspring will be heterozygous dominant for mutism (Tt), resulting in normal hearing
• All their offspring will be heterozygous dominant for deafness (Bb), resulting in normal speech
• No child will exhibit the deaf-mute phenotype.

Dominance and Intensity

• Dominant alleles are responsible for the expression of a trait.
• When a dominant allele is more present, the expressed trait becomes more intense (e.g., a red flower).
• Crosses leading to an increased frequency of dominant alleles result in a more intense expression of the dominant trait.

Monohybrid Cross Resulting in F1 Generation

• Crossing a homozygous round pea (RR) with a homozygous wrinkled pea (rr) will result in F1 generation peas with all round peas (Rr)
• The round (R) allele is dominant over the wrinkled (r) allele
• The F1 generation is heterozygous, inheriting one dominant (R) and one recessive (r) allele.

This quiz explores the inheritance patterns of blood types based on parental genotypes. It specifically investigates the percentage of offspring with blood type A positive resulting from a B heterozygous father and A homozygous mother. Test your understanding of genetic principles related to blood group inheritance.