10. You are studying fin formation in zebrafish and isolate two finless mutants,

Question

10. You are studying fin formation in zebrafish and isolate two finless mutants, which do not have dorsal fins. For reasons we will not detail, you hypothesize that the mutation is recessive and 80% penetrant. To test your hypothesis, you cross the two finless animals and assay their progeny for the presence of a fin. Of 100 progeny, 10 are finless and 90 are wild-type. To determine if this difference between the expected and observed numbers is significant, calculate the chi-square value. a. 0.25 b. 1.25 c. 6.25 d. 10.25 e. None of the above

Explanation / Answer

If the mutation is recessive and two finless mutants are mated, all the progeny are expected to be finless. However, the gene is only 80% penetrant. Which means that only 80% of the progeny will show the trait.

according to this, if there are 100 progeny, 80 should be finless (80%) and 20 should be wild-type.

Actually, of 100 progeny, 10 are finless and 90 are wild type.

Let us make a table.

X2 (Chi square) value is the sum of all values of the last column.

61.25 + 245 = 306.25.

Therefore, the answer is None of the Above.

Observed Expected (O-E)2 (O-E)2/E 10 80 4900 61.25 90 20 4900 245

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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