Genotype, Phenotype, & Punnett Squares

Front

What is a genotype?

Back

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

Front

What is a phenotype?

Back

A phenotype is the physical appearance or observable traits of an organism, resulting from the interaction of its genotype with the environment (e.g., red hair, tall plant).

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene (e.g., TT or tt).

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene (e.g., Tt).

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 probability of getting a homozygous genotype from a cross of TT and Tt?

Back

50%.

Front

What is the probability of getting a heterozygous genotype from a cross of Tt and Tt?

Back

50%.

Front

What is the difference between dominant and recessive alleles?

Back

Dominant alleles mask the effect of recessive alleles in the phenotype. For example, T (dominant) vs. t (recessive).

Front

If a plant has the genotype Tt, what is its phenotype if T is dominant for tallness?

Back

The phenotype would be tall.

Front

What does it mean if an organism is homozygous recessive?

Back

It means the organism has two recessive alleles for a trait (e.g., tt).