7.2 - Populations Flashcards
Define species
A group f organisms that can interbreed to produce fertile offspring.
Define population
All the organisms of a particular species that liv in the same place.
Define gene pool.
The range of different alleles existing for a particular locus within a population.
Define allele frequency.
The proportion of a certain allele within a gene pool, expressed as a decimal or percentage.
What is the Hardy-Weinberg principle?
Allows us to estimate the frequency of alleles in a population, as well as if allele frequency is changing over time.
Give the assumptions made by the Hardy-Weinberg principle.
- No mutations occur to create new alleles
- No migration in or out of the population
- No selection so alleles are all equally passes on to the next generation
- Random mating
- Large population
Explain the Hardy-Weinberg equation for calculating allele frequency.
The frequencies of each allele for a characteristic must add up to 1.0. The equation is therefore; p+q=1
Where p = frequency of the dominant allele
and q = frequency of the recessive allele
Explain the Hardy-Weinberg equation for calculating genotype frequency
The frequencies of each genotype for a characteristics must add up to 1.0. The equation is therefore; p^2 + 2pq + q^2 = 1
Where p^2 = frequency of homozygous dominant
2pq = frequency of heterozygous
q^2 = frequency of homozygous recessive