(3) You are studying two populations of endangered Phlox darwinii (a flowering p
ID: 217801 • Letter: #
Question
(3) You are studying two populations of endangered Phlox darwinii (a flowering plant). In population #1, you observe that within individual flowers, pollen can contact the pistil for self-fertilization. In population #2, you observe that within individual flowers pollen from the same flower rarely contacts the pistil of that flower, reducing self-fertilization. In order to study the effects of self-fertilization, you sequence 20 different loci from multiple individuals in both populations. One locus is called BIB. In both population #1 and #2 you find two alleles at the BIB locus: B and b. In both populations, the frequency of B = 0.3 and the frequency of b = 0.7
(a) For both population #1 and #2, what is the expected heterozygosity at the BIB locus assuming Hardy-Weinberg equilibrium? (6 points)
(b) When you collected the BIB sequence data, you kept track of genotype frequencies at the BIB locus in both populations. You observed that the frequency of Bb heterozygotes was 12% in population #1, and 38% in population #2. Are these genotype frequencies consistent with your observations of possible self-fertilization in the two populations? Briefly explain your reasoning.
Explanation / Answer
a. According to Hardy-Weinberg equillibrium it is p^2 + 2pq + q^2
Where 2pq is the heterozygosity and p and q are freequency of dominant and recessive allele.
So from the given problem two allele freequencies are p = B = 0.3
and q = b = 0.7 . So 2pq = 2 * 0.3 * 0.7 = 0.42.
b. Yes it is consistent with the observation .In population 1 there is self fertilisation so the chance of cross fertilisation is less.We can say flowers are having self fertilisation are of either BB or bb . So all the progenies are either BB or bb respectively.So Bb production is less.
But in case of population 2 there are no self fertilisation but cross fertilisation .So the cross between BB and bb occurs and Bb production is higher than population 1.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.