Founder Effect and Genetic Drift

Question 1

T/F. For disease - related, religious, geographical or other reasons, a small group of individuals may survive or become genetically isolated from the rest of the population (a genetic isolate), w/ subsequent expansion of the isolated group after this ‘population bottleneck ’.

Answer 1

True.

Question 2

In ____, w/c is inherited as an autosomal dominant trait, many current gene carriers are direct descendants of one couple who emigrated from Holland in the 1680s.

Answer 2

variegate porphyria

Question 3

It is believed that as a result of a founder, the rare disorder, ____, characterized by extra digits or polydactyly, congenital heart disease & short stature, became unusually frequent in the Old Order Amish community of Pennsylvania.

Answer 3

Ellis – van Creveld syndrome

Question 4

This term describes the changes in population gene frequencies that occur on account of random differences, from one generation to the next, in the frequency of transmission of particular alleles. i.e. chance effects of Mendelian segregation.

Answer 4

Genetics drift

Question 5

T/F. Allele frequency fluctuations tend to have greater effects in big populations.

Answer 5

Small populations

Question 6

In practice, it is found that genetic drift generally causes rapid significant differences in disease frequencies only when the reproductive population size is less than _____.

Answer 6

100 individuals.