Punnett Square

Front

What is a Punnett Square?

Back

A Punnett Square is a diagram used to predict the genetic makeup of offspring from a cross between two parents.

Front

What does the term 'genotype' refer to?

Back

Genotype refers to the genetic constitution of an individual, represented by the alleles inherited from the parents.

Front

What is the difference between homozygous and heterozygous genotypes?

Back

Homozygous genotypes have two identical alleles (e.g., RR or rr), while heterozygous genotypes have two different alleles (e.g., Rr).

Front

What does 'dominant' mean in genetics?

Back

A dominant allele is one that expresses its trait even when only one copy is present in the genotype.

Front

What does 'recessive' mean in genetics?

Back

A recessive allele is one that only expresses its trait when two copies are present in the genotype.

Front

If round seeds (R) are dominant to wrinkled seeds (r), what is the phenotype of a plant with genotype RR?

Back

The phenotype is round seeds.

Front

What is the probability of obtaining a homozygous recessive offspring from a cross of Rr x Rr?

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 and the probability of that genotype occurring.

Front

What is the expected phenotypic ratio from a monohybrid cross of two heterozygous parents (Rr x Rr)?

Back

The expected phenotypic ratio is 3:1 (3 round seeds to 1 wrinkled seed).

Front

What is the genotype of a plant that is homozygous dominant for purple color (P)?

Back

The genotype is PP.