3.7.2 Populations

Question 1

What’s a population

Answer 1

Group of organisms of the same species occupying a particular space at a particular time that can potentially interbreed

Question 2

How do species exist

Answer 2

One or more populations

Eg squirrels in Leicester and notts

Question 3

What’s a gene pool

Answer 3

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

Question 4

What’s allele frequency

Answer 4

The number of times an allele occurs within the gene pool

Question 5

What’s the hardy Weinberg principal

Answer 5

Mathematical model predicting that allele frequency will not change from generation to generation

In an exam you must state the above and a condition ie no mutations etc

Question 6

Hardy Weinberg equation

Answer 6

p^2 + 2pq + q^2 = 1

p= frequency of dominant allele
q= frequency of recessive allele
(These refer to allele frequencies)
p^2= homozygous dominant
2pq= heterozygous
q^2= homozygous recessive
(These refer to genotypes)

We can also use another equation
p + q = 1

Question 7

What are the conditions for the hardy Weinberg principle to hold true

Answer 7

No mutations arise
Isolated population (no migration)
Large population
Mating within the population is random
No selection, alleles have an equal chance to be passed onto the next generation