lorblindness is an X-linked recessive trait. A normal woman, but a carrier, has
ID: 280455 • Letter: L
Question
lorblindness is an X-linked recessive trait. A normal woman, but a carrier, has children with a normal man. What is the chance that their first child will be red-green colorblind ? (a pts) A. 0% B.12.5% C.25% D.50% E.75% F. 100% In the space at right, neatly setup & show your Punnett square. Use standard notation to indicate X-linkage and define your symbols for full credit(a pts) 2.2 If the couple in 2.1 has had 3 sons (no twins), what is the chance that they all will be red-green colorblind? (2 pts) A, 50% B.25% C.12.5% D, about 6% E.about3% F. about 1.5% 2.3 If a normal woman whose father was red-green colorblind has children with a red-green colorblind man, what is the chance that they will have red-green colorblind daughter ?//a red-green colorblind son? (a pts) A. o% // 0% B. o% //go% C50%//go% D50 %//loo % E. 100%//go % F.100%//100%Explanation / Answer
21. Option D is correct.
WT gene = XC
Mutant gene = Xc
Parental cross: XCXc X XCY
Progeny: XCXC XCY XCXc XcY
Half the progeny are color blind.
22. Option C is correct.
The probability for a son to be affected = 1/2
The probability for 3 sons to be affected = 1/2 X 1/2 X 1/2 = 1/8 = 12.5%
23. Option C is correct.
Parental cross: XCXc X XcY
Progeny: XCXc XCY XcXc XcY
The probability for a colour blind daughter = 1/2 = 50%
The probability for a colour blind son = 1/2 = 50%
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.