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.

Front

What does it mean if an allele is dominant?

Back

A dominant allele is one that can mask the effect of a recessive allele. It is represented by a capital letter.

Front

What does it mean if an allele is recessive?

Back

A recessive allele is one that is masked by a dominant allele. It is represented by a lowercase letter.

Front

In a Punnett Square, what do the letters represent?

Back

The letters represent the alleles of the parents. Capital letters indicate dominant alleles, while lowercase letters indicate recessive alleles.

Front

If a plant has the genotype Tt, what does this mean?

Back

The plant has one dominant allele (T) and one recessive allele (t), making it tall.

Front

What is the probability of getting a tall plant from a cross between TT and tt?

Back

100% of the offspring will be tall because all will inherit the dominant T allele.

Front

How do you calculate the probability of an offspring having a specific trait?

Back

You count the number of times the trait appears in the Punnett Square and divide it by the total number of possible outcomes.

Front

What is the likelihood that the offspring will be green (G) if both parents are heterozygous (Gg)?

Back

50% likelihood of being green.

Front

What is the expected ratio of tall to short plants when crossing Tt x Tt?

Back

The expected ratio is 3 tall plants to 1 short plant (3:1).

Front

Why is DNA important in genetics?

Back

DNA serves as the blueprint for traits of all living things, determining how organisms develop and function.