Chapter 23 Chapter Questions

Front

What are alleles?

Back

Alternative forms of a gene for a single trait, such as blue eyes or brown eyes.

Front

In a Mendelian monohybrid cross involving two homozygous genotypes, which generation is always completely heterozygous?

Back

F1 generation.

Front

If a pea plant is heterozygous for a trait where some plants fail to produce chlorophyll, what are the likely phenotypes of the resulting offspring when self-pollinated?

Back

About one-fourth will be white and three-fourths green.

Front

What is the genotype of a woman who can roll her tongue (dominant) married to a man who cannot, if two of their four children can roll their tongues?

Back

Woman: Aa; Man: aa.

Front

What does the term 'genotype' indicate?

Back

The gene combination of an individual.

Front

What is the difference between a dominant and a recessive trait?

Back

A dominant trait is expressed in the phenotype even if only one allele is present, while a recessive trait is expressed only when two recessive alleles are present.

Front

What is a monohybrid cross?

Back

A genetic cross between individuals that involves one pair of contrasting traits.

Front

What does homozygous mean?

Back

Having two identical alleles for a particular gene.

Front

What does heterozygous mean?

Back

Having two different alleles for a particular gene.

Front

What is the phenotypic ratio expected from a monohybrid cross?

Back

Typically, a 3:1 ratio of dominant to recessive phenotypes.