Genetic Diversity and the Hardy-Weinberg Principle

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Questions and Answers

What is the gene pool of a population?

The geographical distribution of a species

The environmental factors affecting a population

The number of individuals in a population

The sum of the genes and their different alleles (correct)

Which of the following must occur for a population to maintain genetic equilibrium according to the Hardy-Weinberg Principle?

Natural selection should actively influence allele frequencies

No mutations must occur (correct)

Gene flow must be encouraged

Small population size is necessary

What role do population geneticists play in studying genetic diversity?

They study the health and stability of populations and microevolution (correct)

They catalog all species within an ecosystem

They conduct trials to enhance crop yield

They determine the available habitats for populations

Which condition does NOT contribute to maintaining genetic equilibrium?

Natural selection can operate freely Signup and view all the answers

Which factor can lead to changes in gene frequencies within a population?

Gene flow through migration Signup and view all the answers

What is the correct definition of allele frequency?

The proportion of a specific allele within the entire population. Signup and view all the answers

Which Hardy-Weinberg equation represents the frequency of heterozygotes?

2pq Signup and view all the answers

What can lead to evolutionary change in a population?

Mutation, genetic drift, and gene flow. Signup and view all the answers

If a trait is dominant and represented by p in the Hardy-Weinberg equation, which of the following correlates with the phenotype frequency of that trait?

p2 + 2pq Signup and view all the answers

What does gene flow refer to in evolutionary biology?

Exchanging alleles between two populations. Signup and view all the answers

What is true about non-random mating in natural populations?

It often leads to preference for certain traits. Signup and view all the answers

Which of the following statements is correct regarding genotype frequency?

It refers to the number of individuals with a specific genotype. Signup and view all the answers

What potential effect can mutation have on a population?

It creates genetic diversity by introducing new alleles. Signup and view all the answers

Signup and view all the answers

Study Notes

Genetic Diversity in Populations

A population is a group of organisms of the same species living in the same area
Within a population are many genes
The gene pool includes all genes and their alleles
Population geneticists study the gene pool to assess population health and microevolutionary changes

The Hardy-Weinberg Principle

A mathematical method to study the gene pool
Predicts a population's gene pool remains stable if other factors are constant
Any changes in gene frequencies over time can be observed
For equilibrium (no evolution):
- No mutations introducing new alleles
- No gene flow (migration)
- Random mating
The population must be large (to prevent genetic drift) and no natural selection occurs

Genotype, Phenotype, and Allele Frequency

Genotype frequency: count of organisms with a specific genotype
Phenotype frequency: count of organisms with a specific phenotype
Allele frequency: proportion of a particular allele in the entire population

The Hardy-Weinberg Equations

p² + 2pq + q² = 1
- p and q are allele frequencies
- p² = homozygous dominant frequency
- q² = homozygous recessive frequency
- 2pq = heterozygous frequency
p + q = 1

Sample Calculations

Example calculations are from text pages 722, 8a, and 8b

Examples

Example involving a population of pigs, where 80% display the dominant pink coat color trait and 20% have the recessive black coat color.
Calculation of allele and genotypic frequencies is required

Evolutionary Change

Gene pools can be unstable
Mutation
- Randomly occurring events in gametes
- Creates genetic diversity
- Can be neutral, beneficial, or harmful
Lack of diversity risks extinction
Gene flow
- Alleles exchanged between populations due to migration
- Increases genetic variability
Natural selection
- Mutations provide raw material
- Example of sickle cell anemia
- Heterozygote advantage
Non-random mating
- Mates chosen based on traits or behaviours
  - May lead to sexual dimorphism
Genetic drift
- Occurs in all populations, especially small ones
- Change in gene pool due to chance
- Founder effect (isolated population with a subset of original gene pool)
Bottleneck effect
- A sudden decrease in population size reduces gene pool diversity

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Description

This quiz covers the concepts of genetic diversity within populations, focusing on the gene pool and the role of population geneticists. It also explores the Hardy-Weinberg Principle, a mathematical approach to studying gene stability and the conditions necessary for a population to remain in equilibrium. Test your understanding of genotype, phenotype, and allele frequencies as you delve into population genetics.