Question

Question 19 1 pts Which of the following is NOT true about traits affected by more than one gene? The combination of selection and recombination due to sexual reproduction can produce new, more extreme phenotypes not previously seen in the population When a phenotype is dependent on the interaction between two genes, and is not just the sum of their effects independently, this is called an epistatic interaction The effects of selection on one trait never influence the trait values for a different character O If a gene has pleiotropic effects on two characters, and the directions of selection on these characters oppose one another, this can prevent changes in the allele frequency of that gene Question 20 1 pts Suppose that in a population of finches, the average beak depth is 10 cm, and adult beak depth ranges from 8 cm to 14 cm. A drought occurs, and only adults with beak depths greater than 11 cm are able to crack the few hard seeds that are produced. Thus, the average beak depth in adults that survive and reproduce is 12 cm. The narrow-sense heritability (h2) of beak depth in this population is 0.5. Based on the breeder's equation (R= hPS) what will be the average beak depth in the next generation? O 11 cm 12 cm O 1 cm 13 cm

Answer 1

Question 19: Answer : If a gene has pleotropic effects on two characters and the directions of selection on these characters oppose one another, this can prevent chandes in the allelle frequency of that gene

Explaination: Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits.

Question 20: Answer - 1 cm

Explaination:

R =( h2 S) where S is selection differential. Here the difference of the average beak depth. So Response R in the next generation is:

R = 0.50 X ( 12 cm -10 cm)

= 0.50 X (2 cm)

   = 1 cm.