Understanding Dominant and Recessive Traits

What do the terms dominant and recessive describe?

• The inheritance patterns of certain traits

• The color of an animal's fur

• The speed of a cheetah

• The size of an organism

How many copies of each gene do sexually reproducing species have?

• One

• Two

• Three

• Four

What is required for a recessive allele to produce a recessive phenotype?

• Three copies from both parents

• Two copies, one from each parent

• No copies are needed

• One copy from one parent

What shape are the red blood cells in people with sickle-cell disease?

• Round

• Square

• Sickle-shaped

• Triangular

What is the inheritance pattern of malaria resistance in sickle-cell carriers?

• Co-dominant

• Dominant

• Recessive

• Incomplete

What protein is affected by the sickle-cell allele?

• Keratin

• Hemoglobin

• Collagen

• Insulin

What happens to red blood cells with sickle-cell alleles under low-oxygen conditions?

• They become more flexible

• They stick together

• They change color

• They grow larger

What is a common myth about dominant phenotypes?

• They are always the same as recessive phenotypes

• They are always unrelated to recessive phenotypes

• They are always less common than recessive phenotypes

• They are always more common than recessive phenotypes

What is the genetic term for an organism with two identical alleles for a trait?

• Recessive

• Heterozygous

• Homozygous

• Dominant

Which of the following is an example of a co-dominant trait?

• Curly hair

• Freckles

• Blue eyes

• Blood type AB