Punnett Squares

Front

What is a Punnett Square?

Back

A Punnett Square is a diagram used to predict the outcome of a genetic cross by showing the possible combinations of alleles from the parents.

Front

What do the letters in a Punnett Square represent?

Back

The letters represent alleles, where uppercase letters denote dominant alleles and lowercase letters denote recessive alleles.

Front

What is the genotype of an organism?

Back

The genotype is the genetic makeup of an organism, represented by the combination of alleles (e.g., AA, Aa, aa).

Front

What is the phenotype of an organism?

Back

The phenotype is the observable physical or biochemical characteristics of an organism, determined by its genotype.

Front

What is a homozygous genotype?

Back

A homozygous genotype has two identical alleles for a trait (e.g., WW or ww).

Front

What is a heterozygous genotype?

Back

A heterozygous genotype has two different alleles for a trait (e.g., Ww).

Front

In a genetic cross, what does the term 'dominant' mean?

Back

A dominant allele is one that expresses its trait even when only one copy is present (e.g., T in Tt).

Front

In a genetic cross, what does the term 'recessive' mean?

Back

A recessive allele is one that only expresses its trait when two copies are present (e.g., tt).

Front

What is the probability of producing a homozygous recessive offspring from a Tt x Tt cross?

Back

The probability is 25%.

Front

How do you determine the probability of different genotypes from a Punnett Square?

Back

Count the number of times each genotype appears in the Punnett Square and divide by the total number of outcomes.