Punnett Squares - Complete Dominance

Front

What is a genotype?

Back

A genotype is the genetic makeup of an organism, represented by the alleles it possesses, such as 'AA', 'Aa', or 'aa'.

Front

What does 'heterozygous' mean?

Back

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

Front

What does 'homozygous' mean?

Back

Homozygous refers to having two identical alleles for a particular gene, such as 'AA' or 'aa'.

Front

What is a dominant allele?

Back

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

Front

What is a recessive allele?

Back

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

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 is the expected genotype ratio from a cross between two heterozygous parents (Rr x Rr)?

Back

The expected genotype ratio is 1 RR : 2 Rr : 1 rr.

Front

What is the expected phenotype ratio from a cross between two heterozygous parents (Rr x Rr) if R is dominant?

Back

The expected phenotype ratio is 3 dominant : 1 recessive.

Front

If a homozygous dominant plant (TT) is crossed with a homozygous recessive plant (tt), what will be the genotype of the offspring?

Back

All offspring will be heterozygous (Tt).

Front

What is the probability of obtaining a recessive phenotype from a cross between two heterozygous parents (Rr x Rr)?

Back

The probability is 25%.