Punnett Square Practice

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 does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene, such as RR or rr.

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene, such as Rr.

Front

What is the genotype for round seeds if round (R) is dominant to wrinkled (r)?

Back

The genotype for round seeds can be either homozygous dominant (RR) or heterozygous (Rr).

Front

What is the phenotype for a genotype of 'Yy' where yellow (Y) is dominant to white (y)?

Back

The phenotype for 'Yy' is yellow flowers.

Front

How do you determine the probability of a trait using a Punnett Square?

Back

To determine the probability of a trait, count the number of times the desired genotype appears in the Punnett Square and divide by the total number of outcomes.

Front

What is the probability of having a child with blue eyes if both parents are heterozygous for brown eyes (Bb)?

Back

The probability is 25%.

Front

What does it mean if a trait is recessive?

Back

A recessive trait is expressed only when an individual has two copies of the recessive allele (e.g., 'rr').

Front

What is the difference between genotype and phenotype?

Back

Genotype refers to the genetic makeup of an organism (e.g., RR, Rr, rr), while phenotype refers to the observable traits (e.g., round or wrinkled seeds).

Front

If a Punnett Square shows 'TT', what does this indicate about the offspring?

Back

'TT' indicates that the offspring is homozygous dominant for that trait.