Genetics and Punnett Squares

Front

What is the definition of phenotype?

Back

The observable physical characteristics of an organism, determined by its genotype.

Front

What is the definition of genotype?

Back

The genetic makeup of an organism, consisting of the alleles inherited from its parents.

Front

What does homozygous mean?

Back

An organism that has two identical alleles for a particular trait (e.g., BB or rr).

Front

What does heterozygous mean?

Back

An organism that has two different alleles for a particular trait (e.g., Rr).

Front

What is heredity?

Back

The passing of traits from parent to offspring.

Front

What is the purpose of a Punnett Square?

Back

To predict the probability of certain traits in offspring based on the genotypes of the parents.

Front

If a blue-eyed father (rr) and a brown-eyed mother (Rr) have a child, what is the probability that their child will have blue eyes?

Back

50%.

Front

What is a dominant trait?

Back

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

Front

What is a recessive trait?

Back

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

Front

What are alleles?

Back

Different forms of a gene that can exist at a specific locus on a chromosome.