Punnett Squares

Front

What are the possible genotypes for a cross between two heterozygous pea plants?

Back

TT = 25%, Tt = 50%, tt = 25%.

Front

What is the definition of phenotype?

Back

An organism’s physical appearance or visible traits.

Front

What is an example of a dominant trait in pea plants?

Back

Yellow pea seeds.

Front

What genotype would go in box 3 of a Punnett square for a cross between Bb and Bb?

Back

Bb.

Front

What is a dominant allele?

Back

An allele whose trait always shows up in the organism when the allele is present; the 'stronger' gene.

Front

What is a recessive allele?

Back

An allele whose trait is masked in the presence of a dominant allele.

Front

How do you determine the genotype of an organism?

Back

By using a Punnett square to analyze the genetic crosses.

Front

What does a Punnett square illustrate?

Back

The possible genetic combinations from a cross between two organisms.

Front

What is the significance of the 1:2:1 ratio in a Punnett square?

Back

It represents the expected genotypic ratio from a monohybrid cross.

Front

What is the difference between homozygous and heterozygous genotypes?

Back

Homozygous has two identical alleles (e.g., TT or tt), while heterozygous has two different alleles (e.g., Tt).