Activity II, Monohybrid Crosses do 1) Phenylketonuria (PKU) is autosomal recessi

Question

Activity II, Monohybrid Crosses do 1) Phenylketonuria (PKU) is autosomal recessive. A man and a woman are both carriers for PKU. Show a Punnett square for the cross between them and answer the following questions. Show your work (e.g. 1/2x 1/2-1/4) a. What is the probability that a child of theirs will be a boy with PKU? b. If they have 3 children, what is the probability that all 3 have PKU? c. If they have 3 children, what is the probability that all 3 are normal? d. What is the probability that 1 or more (of the 3) will have PKU? 2) A rooster with gray feathers is mated to a gray hen. Among their offspring, 15 chicks are gray, 6 are black, and 8 are white. a. What is the simplest explanation for the inheritance of feather color in chickens? What is the genotype of a gray chicken? What offspring do you expect from the mating of a gray rooster and a b. c. black hen? Show a Punnett square

Explanation / Answer

Answer:

1).

XX: Aa x XY: Aa---Parents

XA

Xa

YA

Ya

XA

XX; AA (normal girl)

XX; Aa (normal girl)

XY; AA (normal boy)

XY; Aa (normal boy)

Xa

XX; Aa (normal girl)

XX; aa (PKU girl)

XY; Aa (normal boy)

XY; aa (PKU boy)

Normal girl = 3/8

PKU girl = 1/8

Normal boy = 3/8

PKU boy = 1/8

PKU children (including boy and girl) = 2/8 = 1/4

Normal children (including boy and girl) = 3/8 + 3/8 = 6/8 = 3/4

a). The probability that a child of theirs will be a boy with PKU = 1/8

b). 1/4 x 1/4 x 1/4 = 1/64

c). ¾ x ¾ x ¾ = 27/64

d). ¾ x ¼ x ¼ = 3/16

XA

Xa

YA

Ya

XA

XX; AA (normal girl)

XX; Aa (normal girl)

XY; AA (normal boy)

XY; Aa (normal boy)

Xa

XX; Aa (normal girl)

XX; aa (PKU girl)

XY; Aa (normal boy)

XY; aa (PKU boy)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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