Question

1 IW (A) Explain the following concepts. 2 marks) [2 marks) 2 marks 1. Population (in population genetics) 2. Hardy Weinberg Equilibrium 3. Mendel's laws of segregation (B) Consider a self-fertilizing population of plants that consists of 25% AA, 50% Aa, and 25% . Write down the genotype frequencies of AA, Aa, and aa after one generation of self- fertilization, assuming that there is a constant reproduction rate for all genotypes 4 marks 2 marks 2. At this generation, show the Inbreeding Coefficient. (C) Consider an autosomal recessive disease KK. Compound heterozygosity in medical genetics is the condition of having two distinct recessive alleles at a particular locus that can cause genetic disease in a heterozygous state. KK belongs to such a case. Specifically, there are three alleles for the related disease gene: S, s1 (mutant 1), and s2 (mutant 2). S is a dominant healthy allele while both sl and s2 are recessive relative to S. Any of the genotypes sl/sl, sl/s2, and s2/s2 results in KK. A sample from a population is assayed. There are, 300 S/S, 150 S/s1, 100 S/s2, 50 s l/s l , 40 s 1%2 , and 10 s2/s2. 3 marks What are allele fre quencies for S, sl and s2? 2. What is the expected chance of any person in the population having two different 3 marks 3. Test the hypothesis of HWE using a Chi-square test, given a level of significance 0.05 7marks mutations s1 and s2 (compound heterozygotes) assuming HWE

Answer 1

Please find the answers below:

Answer 1

Part 1: Population is defined as a group of inbreeding individuals which produce fertile offsprings. Due to constant action of various forces of evolution, a population remains under constant scope of evolution.

Part 2: Hardy Weinberg law can be understood as a set of mathematical equations where the allele frequencies of a set of genes remaining under equilibrium, provided following conditions are met:

1. Population is large
2. Random mating takes place
3. No mutation occurs
4. No migration occurs
5. Segregation of allele takes place

Thius, considering the allele frequencies of two alleles being q and p, the equatio that follow are

p^{2 +} q² + 2pq =1 and p+q=1.

Part 3: Mendel has proposed three laws of genetics out of which the second law is law of segregation. According to this law, the alles for a trait separate from each other during meiosis to generate haploid gametes which further can underground sexual reproduction mediated crossing over and recombination. This, these recombinations help in generating variations among individuals.