Final Examination Codon Table Final Examination 42 9 points

Final Examination Codon Table Final Examination 42. (9 points) Red hair (autosomal recessive) is found in approximately 4 percent of the people in Norway. If we assume that the Norwegian population is in Hardy-Weinberg equilibrium with respect to hair color: A) What are the frequencies ofthe red hair (r) and non-red hair (R) alleles? B) What is the frequency of heterozygotes? 43. (6 points) Darwin\'s theory of evolution was developed around three central principles roteins

Solution

Answers:

(42) (A)

Since red hair is recessive (rr), we get

r² = 4/100

so, r = 0.2

According to Hardy Weinberg equilibrium, R² + 2Rr + r² = 1...........................(1)

Also, R + r = 1

Therefore R = 1 - 0.2 = 0.8

Thus, frequencies of the red and non red alleles are 0.2 (r) and 0.8 (R).

(B) Frequency of heterozygote = 2Rr

= 2 * 0.8 * 0.2

= 0.32

(C) Proportion of matings that can have red hair (rr) can be calculated as under:

(i) Rr * Rr = 0.32 * 0.32 = 0.1024

(ii) Rr * rr = 0.32 * 0.04 * 2 = 0.0256

(iii) rr * rr = 0.04 * 0.04 = 0.0016

So, proportion with red hair = 0.1296

Therefore, thw proportion of matings that cannot give red hair = 1 - 0.1296 = 0.8704

(43) The 3 central principles of Darwin\'s theory of evolution are stated below:

(a) A species is a group of organisms which can interbreed and produce fertile offsprings.

(b) Living organisms have decended from previous organisms (species) with modifications.

(c) Natural selection explains for adaptation and speciation. It states that phenotypic variation exists within populations which are heritable. The individuals with the heritable trait better suited to the environment will survive and others will become extinct (Survival of the fittest).