Punnett Squares 2

Front

What is a genotype?

Back

The letters that make up the genetic code for a trait.

Front

What does homozygous dominant mean?

Back

An organism with two identical dominant alleles for a trait (e.g., AA).

Front

What is the probability of getting a recessive trait in a Punnett square?

Back

It depends on the genotypes of the parents; can be 0%, 25%, 50%, or 75%.

Front

What is the phenotype?

Back

The observable characteristics or traits of an organism.

Front

What does heterozygous mean?

Back

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

Front

In a Punnett square, what does each box represent?

Back

Each box represents a possible genotype of the offspring from the parents' alleles.

Front

If a homozygous dominant brown mouse (BB) is crossed with a homozygous recessive white mouse (bb), what will the offspring's phenotype be?

Back

All offspring will have brown fur (Bb).

Front

What is the purpose of a Punnett square?

Back

To predict the possible genotypes and phenotypes of offspring from parental crosses.

Front

What is the expected ratio of phenotypes in a monohybrid cross?

Back

Typically 3:1 for dominant to recessive traits.

Front

What does it mean if a trait is recessive?

Back

It only expresses in the phenotype if two recessive alleles are present (e.g., aa).