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 do the letters T and t represent in genetics?

Back

In genetics, uppercase letters (e.g., T) typically represent dominant alleles, while lowercase letters (e.g., t) represent recessive alleles.

Front

What is the genotype of a homozygous dominant organism?

Back

The genotype of a homozygous dominant organism consists of two identical dominant alleles (e.g., TT).

Front

What is the genotype of a homozygous recessive organism?

Back

The genotype of a homozygous recessive organism consists of two identical recessive alleles (e.g., tt).

Front

What is a heterozygous genotype?

Back

A heterozygous genotype consists of one dominant allele and one recessive allele (e.g., Tt).

Front

How do you determine the probability of a specific phenotype in offspring?

Back

To determine the probability of a specific phenotype, you analyze the genotypes produced in a Punnett Square and calculate the ratio of the desired phenotype to the total number of offspring.

Front

What is the phenotypic ratio of a monohybrid cross between two heterozygous parents?

Back

The phenotypic ratio of a monohybrid cross between two heterozygous parents (Tt x Tt) is typically 3:1, where 3 represent the dominant phenotype and 1 represents the recessive phenotype.

Front

In a Punnett Square, where are the parent alleles written?

Back

The parent alleles are written outside of the boxes, typically along the top and left side of the square.

Front

What is the probability of obtaining a homozygous recessive offspring from a cross between a heterozygous and a homozygous recessive parent?

Back

The probability of obtaining a homozygous recessive offspring from a cross between a heterozygous (Tt) and a homozygous recessive (tt) parent is 50%.

Front

What phenotype results from crossing a homozygous dominant with a homozygous recessive organism?

Back

The phenotype resulting from crossing a homozygous dominant organism (e.g., TT) with a homozygous recessive organism (e.g., tt) is always the dominant phenotype.