153. (3 pts) Infantile Tay-Sachs disease is a recessive, autosomal disease. Youn

Question

153. (3 pts) Infantile Tay-Sachs disease is a recessive, autosomal disease. Young children with Tay-Sachs disease overproduce cell membrane components that prevent brain nerve cells from functioning. Death occurs before the age of four years. John is a healthy adult. Likewise, his parents were healthy. However, John's two sisters had Tay-Sachs disease. What is the probability that John is a carrier (heterozygous) for the Tay-Sachs mutation? B. 1/3 C. 2/3 D. 2/9 E 4/9 154. (3 pts) In Drosophila, the he (hairy eye) allele is recessive to the wild type he* (normal eye) allele. Also, the bl (big leg) allele is recessive to the blt (normal leg) allele. A hairy eye, big leg female from a true breeding population was crossed to a true breeding wild type male. An F1 female was crossed to a wild type male from a true breeding population. The genetic distance between h and bl is 20 Centimorgans on the X chromosome. What numbers of progeny would you expect to detect if 2,000 progeny are analyzed? Phenotype normal eye Male 400 1000 400 1000 100 normal leg hairy eye, big leg 400 400 100 hairy eye, normal Normal eye, big normal eye, hairy eye,big leg0 leg leg normal leg 100 100 1000 100 100 400 400 400 400 100 Female 1000 1000 400 100 hairy eye, normal 100 400 Normal eye, big 100 100 400 leg Work space

Explanation / Answer

153) B

154) B

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.