In a cross between two doubly heterozygous Ursa gummi, we observe 415 Melting Ur
ID: 73135 • Letter: I
Question
In a cross between two doubly heterozygous Ursa gummi, we observe 415 Melting Ursa gummi and 50 Melting-resistant Ursa gummi. If the Melting phenotype is the dominant phenotype, make a decision as to whether these data are consistent with the duplicate dominant epistatic mode of inheritance. Make your decision based on a significance level threshold of 5%.
A. Decision is: no, they are not. Chi-square p-value > 0.05.
B. Decision is: no, they are not. Chi-square p-value < 0.05.
C. Decision is: Yes, they are. Chi-square p-value > 0.05.
D. Decision is: Yes, they are. Chi-square p-value < 0.05.
E. Decision is: no, they are not. The mode of inheritance is Recessive Epistasis.
THE ANSWER IS NOT D !!!!
A. Decision is: no, they are not. Chi-square p-value > 0.05.
B. Decision is: no, they are not. Chi-square p-value < 0.05.
C. Decision is: Yes, they are. Chi-square p-value > 0.05.
D. Decision is: Yes, they are. Chi-square p-value < 0.05.
E. Decision is: no, they are not. The mode of inheritance is Recessive Epistasis.
THE ANSWER IS NOT D !!!!
Explanation / Answer
Option C
In case of dominant epistasis the ratio observed is 9:3:1. Since melting Ursa gummi is dominant the results should be consistent with around 200 melting ursa gummi and 50 melting-resistant ursa gummi showing dominant epistasis. Given are 415 melting ursa gummi (dominant phenotype) and 50 melting-resistant ursa gummi as a result of heterozygous cross. This result is consistent with 9:3:1 ratio of duplicate dominant epistasis. The significance level threshold of 5% means that a p-value greater than 0.05 means that this hypothesis is acceptable. Thus, option C is the correct answer.