Genotype, Phenotype, & Punnett Squares

Front

What is a genotype?

Back

The possible combination of alleles in a gene.

Front

What is a phenotype?

Back

The physical expression of the genes.

Front

What does homozygous mean?

Back

Having two identical alleles for a trait (e.g., AA or aa).

Front

What does heterozygous mean?

Back

Having two different alleles for a trait (e.g., Aa).

Front

If G = green and g = yellow, what is the genotype for a green plant?

Back

GG or Gg.

Front

What is the probability of getting a homozygous recessive offspring from two heterozygous parents?

Back

25%.

Front

What does it mean if a trait is dominant?

Back

It will be expressed in the phenotype even if only one dominant allele is present.

Front

What does it mean if a trait is recessive?

Back

It will only be expressed in the phenotype if two recessive alleles are present.

Front

In a Punnett square, what do the letters on the top and side represent?

Back

The alleles contributed by each parent.

Front

What is a Punnett square used for?

Back

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