3.6 Punnett squares Flashcard

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 homozygous mean?

Back

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

Front

What does heterozygous mean?

Back

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

Front

What is the genotype for tall plants if T = tall and t = short?

Back

The genotypes for tall plants can be TT (homozygous dominant) or Tt (heterozygous).

Front

What is the phenotype for short plants if T = tall and t = short?

Back

The phenotype for short plants is represented by the genotype tt (homozygous recessive).

Front

How do you determine the probability of a trait using a Punnett square?

Back

To determine the probability of a trait, count the number of times the desired genotype appears in the Punnett square and divide by the total number of possible genotypes.

Front

What is the probability of getting a homozygous recessive offspring from two heterozygous parents (Tt x Tt)?

Back

The probability is 25%.

Front

What does it mean if an organism has a dominant allele?

Back

If an organism has a dominant allele, it will express the dominant trait, even if it has one recessive allele.

Front

What is the expected phenotypic ratio for a monohybrid cross?

Back

The expected phenotypic ratio for a monohybrid cross is typically 3:1 for dominant to recessive traits.

Front

What is the expected genotypic ratio for a monohybrid cross?

Back

The expected genotypic ratio for a monohybrid cross is 1:2:1 for homozygous dominant, heterozygous, and homozygous recessive.