Dihybrid crosses

Front

What is a dihybrid cross?

Back

A genetic cross that involves two traits, each represented by two alleles.

Front

What does the term 'homozygous' mean?

Back

An organism with two identical alleles for a particular trait (e.g., RR or rr).

Front

What does the term 'heterozygous' mean?

Back

An organism with two different alleles for a particular trait (e.g., Rr).

Front

What is the phenotypic ratio of a typical dihybrid cross?

Back

9:3:3:1.

Front

What is the genotype for a pea plant heterozygous for round seeds (R) and homozygous recessive for green seeds (y)?

Back

Rryy.

Front

In a dihybrid cross, what is the probability of obtaining a homozygous recessive offspring for both traits?

Back

1 out of 16 or 6.25%.

Front

What is the expected phenotype of offspring from a cross between RRYY and rryy?

Back

All offspring will be RrYy (round and yellow).

Front

What is the purpose of a Punnett square in genetics?

Back

To predict the genotypes and phenotypes of offspring from a genetic cross.

Front

What is the genotype for a plant that is homozygous for round seeds and heterozygous for yellow seeds?

Back

RRYy.

Front

If a plant has the genotype Aabb, what are the possible gametes it can produce?

Back

Ab, ab.