Genetics: Punnett Squares and Likelihood

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 for a trait to be dominant?

Back

A dominant trait is one that is expressed in the phenotype even when only one copy of the allele is present.

Front

What does it mean for a trait to be recessive?

Back

A recessive trait is one that is only expressed in the phenotype when two copies of the allele are present.

Front

What is the genotype of a heterozygous organism?

Back

A heterozygous organism has two different alleles for a particular gene, represented as 'Tt'.

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What is the genotype of a homozygous dominant organism?

Back

A homozygous dominant organism has two identical dominant alleles for a particular gene, represented as 'TT'.

Front

What is the genotype of a homozygous recessive organism?

Back

A homozygous recessive organism has two identical recessive alleles for a particular gene, represented as 'tt'.

Front

If two heterozygous tall pea plants (Tt) are crossed, what is the expected phenotypic ratio?

Back

The expected phenotypic ratio is 3 tall (75%) to 1 short (25%).

Front

What is the probability of two heterozygous parents (Bb) having a child with a recessive trait?

Back

The probability is 25%.

Front

What does it mean for an organism to be homozygous?

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An organism is homozygous when it has two identical alleles for a specific gene.

Front

What is the purpose of a Punnett Square in genetics?

Back

The purpose of a Punnett Square is to visualize and calculate the probability of offspring inheriting particular traits.