7.2 population Flashcards
What is a species?
A group of organisms that can interbreed to produce fertile offspring.
What is a population?
All the organisms of a particular species that live in the same place.
What is a gene pool?
The range of different alleles existing for a particular locus within a population.
What is 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.
What are the assumptions of 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 passed on to the next generation. ● Random mating. ● Large population.
What is the Hardy-Weinberg equation for allele frequency?
p + q = 1
What does P mean in the equation for allele frequency?
p = frequency of the dominant allele.
What does q mean in the equation for allele frequency?
q = frequency of the recessive allele.
What must be true for the equation for allele frequency?
The frequencies of each allele for a characteristic must add up to 1.0.
What is the Hardy-Weinberg equation for genotype frequency?
p² + 2pq + q² = 1
What must be true for the Hardy-Weinberg equation for genotype frequency?
The frequencies of each genotype for a characteristic must add up to 1.0.
What does p² mean in the equation for genotype frequency?
p² = frequency of homozygous dominant.
What does q² mean in the equation for genotype frequency?
q² = frequency of homozygous recessive.
What does 2pq mean in the equation for genotype frequency?
2pq = frequency of heterozygous.
What is phenotype frequency?
(total individuals with phenotype ÷ total individuals in population) × 100
How do you calculate the phenotype frequency of purple flowers in a population of 9 pea plants with 7 purple and 2 white?
Phenotype frequency = (7 ÷ 9) × 100 = 78%.
How do you calculate the phenotype frequency of white flowers in a population of 9 pea plants with 7 purple and 2 white?
Phenotype frequency = (2 ÷ 9) × 100 = 22%.
What is homozygous dominant?
(BB)
What is heterozygous?
(Bb)
What is homozygous recessive?
(bb)
Why do people with complete achromatopsia have difficulty in seeing detail?
No (functional) cones OR Only rods; cones are connected to a single neuron, cones separate sets of impulses to the brain and rods send a single set of impulses to the brain.
What is a phenotype?
Observable characteristics of an organism which are the result of the genotype as well as environmental factors.
What is a genotype?
All the alleles that an organism carries on its chromosomes.
