In the California poppy, an allele for yellow flowers (C) is dominant over an al
ID: 96874 • Letter: I
Question
In the California poppy, an allele for yellow flowers (C) is dominant over an allele for white flowers (c). At an independently assorting locus, an allele for entire petals (F) is dominant over an allele for fringed petals (f). A plant that is homozygous for yellow and entire petals is crossed with a plant that is white and fringed. A resulting F_1 plant is then crossed with a plant that is white and fringed, and the following progeny are produced: 54 yellow and entire, 58 yellow and fringed, 53 white and entire, and 10 white and fringed. Using a chi-square test to compare the observed numbers with those expected for the cross, what can you conclude in regard to whether the ratios observed occurred due to random variations? With four degrees of freedom, the chi-square value is greater than 14.860 for a probability value of less than 0.005, so the deviation between observed and expected was likely to occur by chance. With four degrees of freedom, the chi-square value is greater than 14.860 for a probability value of less than 0.005, so the deviation between observed and expected was not likely to occur by chance. With three degrees of freedom, the chi-square value is greater than 12.838 for a probability value of less than 0.005, so the deviation between observed and expected was likely to occur by chance. With three degrees of freedom, the chi-square value is greater than 12.838 for a probability value of less than 0.005, so the deviation between observed and expected was not likely to occur by chance The determination cannot be made with the information given.Explanation / Answer
Answer:
Based on the given information:
California poppy - yellow flower allele (C) is dominant over white flower (c)
Allele for entire petal (F) is dominant over fringed petal (f)
Plant homozygous for yellow flower (CC) and entire petal (FF) is crossed with plant that has white flower (cc) and fringed petal (ff)
CCFF x ccff - Resultant progeny will be all CcFf
F1 is then crossed with a plant that is white (cc) and fringed (ff)
CcFf x ccff
Punnett square for this cross is:
So different phenotypes are:
Ratio of phenotypes: 1:1:1:1
Total number of Progeny produced = 54 + 58 + 53 + 10 = 175
54 - yellow and entire
58 - yellow and fringed
53 - white and entire
10 - white and fringed
Number of classes (n) = 4
df = n-1 + 4-1 = 3
So Chisquare value with 3 degree of freedom is 35.03. The P-Value is < 0.00001. The result is significant at p < 0.05.
Hence the correct option is 4th:
cf cf cf cf CF CcFf (yellow & entire) CcFf (Yellow & Entire) CcFf (Yellow & Entire) CcFf (Yellow & Entire) Cf Ccff(yellow & fringed) Ccff(yellow & fringed) Ccff(yellow & fringed) Ccff(yellow & fringed) cF ccFf (white & entire) ccFf (white & entire) ccFf (white & entire) ccFf (white & entire) cf ccff (white & fringed) ccff (white & fringed) ccff (white & fringed) ccff (white & fringed)