Concepts Basic Genetics Review

What is the definition of a genotype?

• The physical appearance of an organism

• The genetic makeup of an organism

• The environment in which an organism lives

• The diet of an organism

Which of the following is an example of a phenotype?

• Bb

• Blue eyes

• Heterozygous

• Homozygous

What does it mean if an organism is homozygous for a trait?

• It has two different alleles for a trait

• It has two identical alleles for a trait

• It has one dominant and one recessive allele

• It has no alleles for a trait

Which of the following represents a heterozygous genotype?

• AA

• aa

• Aa

• BB

What is a dominant allele?

• An allele that is masked by a recessive allele

• An allele that is expressed only in the homozygous state

• An allele that is always expressed when present

• An allele that is never expressed

In a complete dominance scenario, what phenotype will an organism with a genotype of Aa exhibit?

• The recessive trait

• A blend of both traits

• The dominant trait

• Neither trait

What is the purpose of a Punnett square?

• To determine the physical traits of an organism

• To predict the probability of offspring genotypes

• To measure the size of an organism

• To calculate the age of an organism

If a homozygous dominant individual (AA) is crossed with a homozygous recessive individual (aa), what will be the genotype of the offspring?

• AA

• Aa

• aa

• A mix of AA and aa

Which of the following is a recessive allele?

• An allele that is always expressed

• An allele that is masked by a dominant allele

• An allele that is expressed in the heterozygous state

• An allele that is never expressed

In a Punnett square, what do the letters outside the grid represent?

• The phenotypes of the parents

• The genotypes of the parents

• The phenotypes of the offspring

• The genotypes of the offspring