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, showing all possible combinations of alleles.

Front

What does the term 'allele' mean?

Back

An allele is a variant form of a gene that can produce different traits in an organism.

Front

What is the difference between dominant and recessive alleles?

Back

Dominant alleles express their trait even if only one copy is present, while recessive alleles require two copies to express their trait.

Front

What is the genotype of an organism?

Back

The genotype is the genetic makeup of an organism, represented by the combination of alleles (e.g., AA, Aa, aa).

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 incomplete dominance mean?

Back

Incomplete dominance is a genetic situation where neither allele is completely dominant, resulting in a blend of traits in the offspring.

Front

If a plant with genotype RR is crossed with a plant with genotype WW, what will be the genotype of the offspring?

Back

All offspring will have the genotype RW.

Front

What is the probability of obtaining a homozygous recessive offspring (aa) from a cross between Aa and Aa?

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 each parent.

Front

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

Back

The expected phenotype ratio is 3:1 (3 dominant: 1 recessive).