Estimating the risk of inherited genetic disease

Question 1

What does the hardy-weinberg equation state?

Answer 1

Relative proportion of Genotype Frequencies remains the same from generation to generation
Allelle Frequency remains the same from generation to generation
P + Q = 1
P + Q + R = 1

Question 2

What does the HWE assume?

Answer 2

• mutation is ignored
• no gene flow
• large population size
• mating is random
• no selective pressures
• equal allele frequency in sexes

Question 3

In reality, mutations occur. What does these do?

Answer 3

Increase the proportions of new alleles

Question 4

What can introduce new alleles? And what does this lead too?

Answer 4

Migration and intermarriage - leads too new gene frequency

Question 5

What does non-random mating lead too ?

Answer 5

Mutant alleles - more affected homozygotes,

Question 6

what is assortive mating?

Answer 6

forming relationships with people who share characteristics.

Question 7

What is consanguinity?

Answer 7

Marriage between close blood relatives.

Question 8

What is natural selection?

Answer 8

Gradual process where a trait increases or decreases within a population. Good traits survive - ‘survival of the fittest’

Question 9

What two things can occur in a small population?

Answer 9

Genetic drift and founder effect .

Question 10

Explain genetic drift.

Answer 10

Random fluctuation in allele frequency due to chance or random events

Question 11

Describe the founder effect and the bottleneck effect/

Answer 11

bottleneck effect - when some population is wiped out - reduces / changes genetic diversity
founder affect - this new small population creates a larger population