Punnett Square - Independent Practice

Front

What is a phenotype?

Back

A phenotype is the observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences. Example: black hair.

Front

What is a genotype?

Back

A genotype is the genetic constitution of an individual, specifically the alleles present. Example: Bb, BB, or bb.

Front

What does a Punnett Square represent?

Back

A Punnett Square is a diagram used to predict the outcome of a particular cross or breeding experiment, showing the possible genotypes of offspring.

Front

What is a dominant allele?

Back

A dominant allele is a variant of a gene that will express its trait in the phenotype even if only one copy is present. It is represented by a capital letter.

Front

What is a recessive allele?

Back

A recessive allele is a variant of a gene that only expresses its trait in the phenotype if two copies are present. It is represented by a lowercase letter.

Front

How do you calculate the probability of a trait in a Punnett Square?

Back

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

Front

What is the probability of getting a homozygous recessive offspring from a Bb x Bb cross?

Back

The probability is 25%.

Front

What does it mean if an organism is homozygous?

Back

An organism is homozygous if it has two identical alleles for a particular gene, such as BB or bb.

Front

What does it mean if an organism is heterozygous?

Back

An organism is heterozygous if it has two different alleles for a particular gene, such as Bb.

Front

What is the significance of the capital letter in allele representation?

Back

The capital letter represents a dominant allele, which will express its trait in the phenotype.