Chapter 12 Review

Front

What is a genotype?

Back

The genetic makeup of an organism, represented by the combination of alleles (e.g., BB, Bb, bb).

Front

What does homozygous mean?

Back

Having two identical alleles for a particular gene (e.g., BB or bb).

Front

What does heterozygous mean?

Back

Having two different alleles for a particular gene (e.g., Bb).

Front

What is a dominant allele?

Back

An allele that expresses its trait even in the presence of a recessive allele (e.g., D in Dd).

Front

What is a recessive allele?

Back

An allele that only expresses its trait when two copies are present (e.g., bb).

Front

What is a phenotype?

Back

The physical traits or characteristics of an organism resulting from its genotype.

Front

What is a Punnett square?

Back

A diagram used to predict the outcome of a genetic cross by showing the possible allele combinations.

Front

What is the purpose of a test cross?

Back

To determine the genotype of an organism with a dominant phenotype by crossing it with a homozygous recessive organism.

Front

What is the law of segregation?

Back

The principle that during the formation of gametes, the two alleles for a trait separate from each other.

Front

What is the law of independent assortment?

Back

The principle that alleles for different traits are distributed to gametes independently of one another.