Punnett squares

Front

What is a Punnett square?

Back

A Punnett square is a diagram used to predict the genetic makeup of offspring from two parents based on their alleles.

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 constitution of an organism, represented by the alleles it possesses.

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 does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene (e.g., AA or aa).

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene (e.g., Aa).

Front

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

Back

The probability is 25%.

Front

In a Punnett square, what does each box represent?

Back

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

Front

If T = tall and t = short, what is the phenotype of Tt?

Back

The phenotype of Tt is tall, as tall (T) is dominant over short (t).

Front

What is the expected phenotypic ratio of offspring from a cross between two heterozygous parents (Tt x Tt)?

Back

The expected phenotypic ratio is 3 tall: 1 short.