population genetics

Question 1

define selection

Answer 1

process by which organisms are better adapted to the environment survive and breed to pass on favourable alleles to subsequent generations

Question 2

define genotype

Answer 2

alleles of a gene organism posseses

Question 3

define population

Answer 3

group of the same species occupying a particular space at a particular time and can interbreed

Question 4

define gene pool

Answer 4

all the alleles of all the genes of all the individuals in a population at a given time

Question 5

define allelic frequency

Answer 5

the number of times an allele occurs within the gene pool

Question 6

what are the 5 assumptions of the Hardy Weinberg principle

Answer 6

• model is large
• random mating
• no selection (alleles are equally likely to passed onto the next generation)
• has no mutation
• no emigration or immigration (flow of alleles into or out of the population)

Question 7

define variation

Answer 7

the differences that exist between individuals

Question 8

define polygene

Answer 8

large number of genes that have a combined effect

Question 9

explain the 3 causes of variation due to genetics

Answer 9

mutation
- difference in bases = new a/a = new protein = different/advantageous characteristics

meiosis
- independent segregation
- crossing over

random fertilisation
- each sperm is genetically different = sperm that fertilises egg is different to others due to meiosis