Understanding Autosomal Recessive Traits

What is an autosomal recessive trait?

• A trait that is expressed when at least one dominant allele is present

• A trait that is expressed only when two recessive alleles are present

• A trait that is expressed only in males

• A trait that is expressed only in females

Which of the following is an example of an autosomal recessive disorder?

• Huntington's disease

• Cystic fibrosis

• Hemophilia

• Color blindness

Tags

NGSS.HS-LS3-2

If both parents are carriers of an autosomal recessive trait, what is the probability that their child will express the trait?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In a Punnett square, what genotype represents a carrier of an autosomal recessive trait?

• AA

• Aa

• aa

• None of the above

Which of the following statements is true about autosomal recessive inheritance?

• It affects males more than females

• It affects females more than males

• It affects males and females equally

• It only affects individuals with one recessive allele

• They will not express the trait

• They will express the trait

• They are a carrier of the trait

• They have a 50% chance of expressing the trait

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Which of the following is NOT a characteristic of autosomal recessive inheritance?

• Skips generations

• Both parents must be carriers for a child to be affected

• Affected individuals always have affected parents

• Can appear in siblings without appearing in parents

What is the probability that two carriers of an autosomal recessive trait will have a child who is also a carrier?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-3

Which of the following genotypes would result in an individual expressing an autosomal recessive trait?

• AA

• Aa

• aa

• Aa or AA

If a child expresses an autosomal recessive trait, what can be inferred about the parents?

• Both parents must be affected

• At least one parent must be affected

• Both parents must be carriers

• One parent must be a carrier

Tags

NGSS.HS-LS3-1