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.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS4-3

Front

What do the letters in a Punnett Square represent?

Back

The letters represent the alleles of the genes being crossed, with uppercase letters indicating dominant alleles and lowercase letters indicating recessive alleles.

Front

What is a genotype?

Back

A genotype is the genetic makeup of an organism, represented by the combination of alleles (e.g., TT, Tt, tt).

Tags

NGSS.HS-LS1-1

NGSS.HS-LS3-2

Front

What is a phenotype?

Back

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

Tags

NGSS.HS-LS4-3

Front

What is the difference between dominant and recessive traits?

Back

Dominant traits are expressed when at least one dominant allele is present, while recessive traits are only expressed when two recessive alleles are present.

Front

What is codominance?

Back

Codominance is a condition in which both alleles for a gene are fully expressed, resulting in offspring with a phenotype that shows both traits.

Front

What is incomplete dominance?

Back

Incomplete dominance is a genetic situation where one allele does not completely dominate another, resulting in a phenotype that is a blend of the two.

Front

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

Back

To calculate the probability, count the number of times a specific genotype appears in the Punnett Square and divide it by the total number of possible genotypes.

Tags

NGSS.HS-LS3-3

Front

What is the probability of getting a homozygous dominant genotype (TT) from a cross of TT x Tt?

Back

The probability is 50%.

Tags

NGSS.HS-LS3-3

Front

If B = brown fur and b = white fur, what is the probability of getting a brown-furred offspring from a Bb x Bb cross?

Back

The probability is 75%.

Tags

NGSS.HS-LS4-3