Dihybrid crosses

Front

What is a dihybrid cross?

Back

A genetic cross between individuals that differ in two traits, typically involving two pairs of contrasting traits.

Front

What is the expected phenotypic ratio of a dihybrid cross?

Back

9:3:3:1, representing the four possible phenotypes of the offspring.

Front

Define homozygous. Give an example.

Back

Homozygous refers to having two identical alleles for a particular gene, e.g., RR or rr.

Front

Define heterozygous. Give an example.

Back

Heterozygous refers to having two different alleles for a particular gene, e.g., Rr.

Front

What is the role of dominant alleles in a genotype?

Back

Dominant alleles mask the effect of recessive alleles in a heterozygous genotype.

Front

What is the probability of obtaining a homozygous recessive offspring from a dihybrid cross?

Back

The probability is 1/16 or 6.25%.

Front

What does a Punnett square illustrate?

Back

A Punnett square illustrates the possible genetic combinations of offspring from a genetic cross.

Front

What is the significance of the F1 generation in genetics?

Back

The F1 generation is the first filial generation, resulting from a cross between two parental (P) generations.

Front

What is the significance of the F2 generation in genetics?

Back

The F2 generation is the second filial generation, produced by self-fertilizing the F1 generation.

Front

What is the expected genotype ratio from a dihybrid cross?

Back

1:2:1:2:4:2:1:2:1, representing the combinations of alleles.