Hi guys! I need help with the following questions for my homework, thanks!
1. In a plant species, Rinorea niccolifera, the ability to grow in nickel contaminated soil
is determined by a dominant allele. (4)
a) If 70% of the seeds in a randomly mating population are able to germinate in this
contaminated soil, what is the frequency of the resistant allele? (/2)
b) Among plants that germinate, what proportion is homozygous? (/2)
2. A larger group of University professors have 396 blonde students and 557 brunette
students. Assume that blonde is totally recessive. Based on this information, calculate
the following: (/8)
a) The allele frequencies of each allele. (/2)
b) The expected genotype frequencies. (/3)
c) The predicted number of heterozygous individuals in this group. (/1)
d) The expected phenotype frequencies. (/2)
3. A researcher has bred a large, randomly-mated population of gerbils. This population
contains 35% white gerbils. White colouring is caused by the double recessive
genotype, “ww”. Calculate allelic and genotypic frequencies for this population. (/5)
4. Microevolution is the change of frequencies of alleles in the gene pool. Imagine a
population of 100 annual wildflowers, some red and some yellow. The red allele, R, is
dominant; the yellow allele, r, is recessive. There are 36 RR plants in the population,
48 Rr plants, and 16 rr (yellow) plants. (/12)
a) What are the genotype frequencies for the current generation? (/3)
b) What are the frequencies of R and r alleles in the gene pool? (/2)
c) Use the rule of multiplication to calculate the frequencies of the three possible genotypes
of plants in the second generation. (/3)
d) What are the frequencies of R and r alleles in the gene pool for the second generation
(assuming the population stays at 100 individuals)? (/2)
e) What happened to the genotype and allele frequencies in the second generation? What
would you predict for the third generation? Why? (/2)
5. In the year 2386, humans develop the necessary technology to travel in time. You are
a researcher who is particularly interested in population genetics of extinct animals.
Taking advantage of this new technology, you decide to go to the past 9 million years
to conduct field work in Venezuela to study a population of Phoberomys pattersoni,
the world’s largest extinct rodent. The coat color of this rodent varies between tan
(dominant) and brown (recessive). Assume the population is in Hardy-Weinberg
equilibrium. You observed 336 tan Phoberomys and 64 brown Phoberomys during
your study. (/6)
a) What is the frequency of the homozygous recessive genotype? (/1)
b) What is the allele frequency of the dominant (tan) allele in the population? (/1)
c) Of the animals observed, how many were heterozygous? (/1)
You make another trip to Venezuela and this time you observe 650 animals.
d) How many of the 650 animals would you expect to be tan, assuming the population is
still in Hardy-Weinberg equilibrium? (/1)
e) How many of tan animals are homozygous for the dominant allele? (/1)
f) How many of the 650 animals would you expect to be brown, assuming the population is
still in Hardy-Weinberg equilibrium? (/1)
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