Question

1. a person has uhs but their parents have normal hair. what must both parents carry? a. two dominant uhs alleles b. one recessive uhs allele each c. a mutation only in somatic cells d. no copies of the uhs gene 3. if two carriers of the uhs recessive allele have a child, what is the probability their child will have uhs? a. 0% b. 25% c. 50% d. 75% 4. which genotypes would express normal hair?(pick all that apply) a. nn b. nn c. nn 5. if one parent is nn (normal) and the other is nn (carrier), what is the chance of an affected child? a. 0% b. 25% c. 50% d. 75% 6. which type of inheritance best describes uhs? a. codominance b. incomplete dominance c. autosomal recessive (mendelian) d. sex - linked

Explanation:

• Question 2: Since the child has UHS (assuming it's a recessive trait) and parents have normal hair, parents must be carriers. Carriers have one recessive allele.
• Question 3: Using a Punnett square for two carriers (Nn x Nn), the genotypes are NN:Nn:nn = 1:2:1. The probability of nn (UHS) is 25%.
• Question 4: If UHS is recessive (nn), then NN (homozygous dominant) and Nn (heterozygous, carrier) would express normal hair.
• Question 5: Parent genotypes NN x Nn. Offspring genotypes: NN and Nn. No nn (affected) possible.
• Question 6: Autosomal recessive inheritance fits as two carriers (Nn) can have an affected child (nn), and it's not sex - linked (no gender - specific bias indicated), not codominance (no blending) or incomplete dominance (no intermediate phenotype).

Answer:

• 2. B. One recessive UHS allele each
• 3. B. 25%
• 4. A. NN, B. Nn
• 5. A. 0%
• 6. C. Autosomal recessive (Mendelian)