Units 25-26: The Hardy-Weindberg Principle

Question 1

Population

Answer 1

A group of organisms of the same species living together in a defined area and time.

Question 2

Gene Pool

Answer 2

The sum of all the alleles for all the genes in a population.

Question 3

Genotype Frequency

Answer 3

The proportion of a population with a particular genotype, expressed as a decimal.

Question 4

Phenotype Frequency

Answer 4

The proportion of a population with a particular phenotype, expressed as a decimal or percentage.

Question 5

Allele Frequency

Answer 5

The rate of occurrence of a particular allele in a population. Expressed as a decimal.

Question 6

Hardy-Weinberg Principle

Answer 6

Allele frequencies in a population will remain the same from one generation to the next as long as five conditions are met:

1. The population is large enough that chance events will not alter the allele frequencies.
2. Mates are chosen on a random basis.
3. There are no net mutations.
4. There is no migration.
5. There is no natural selection against any of the phenotypes.

Question 7

Genetic Equilibrium

Answer 7

Used to describe a population with no change in allele frequencies over time.

Question 8

Microevolution

Answer 8

The gradual change in allele frequencies in a population.

Question 9

Genetic Diversity

Answer 9

The degree of genetic variation within a species or population.

Question 10

Mutations

Answer 10

Can be beneficial or harmful. Can cause shifts in genetic diversity. Diversify a gene pool.

Question 11

Gene Flow

Answer 11

The net movement of alleles from one population to another due to the migration of individuals.
Increase genetic diversity in populations. Decreases differences among populations.

Question 12

Non-Random Mating

Answer 12

Mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding, rather than mating on a random basis.
Prevents individuals with particular phenotypes from breeding.

Question 13

Genetic Drift

Answer 13

A change in allele frequencies due to chance events in a small breeding population.

Question 14

Founder Effect

Answer 14

The gene pool change that occurs when a few individuals start a new, isolated population.

Question 15

Bottleneck Effect

Answer 15

Gene pool change that results from a rapid decrease in population size.

Question 16

Natural Selection

Answer 16

The only process that leads directly to evolutionary adaptation. Individuals who are better bale to survive and reproduce pass on their favorable variations to the next generation.

Question 17

Heterozygote Advantage

Answer 17

A survival benefit for those individuals who inherit two different alleles for the same trait (Aa), compared to those who are homozygous. For example, the allele for cystic fibrosis may help carriers better resist diarrheal diseases such as cholera.

Question 18

Factors Influencing Biotic Potential

Answer 18

1. Number of offspring per reproductive cycle.
2. The number of offspring that survive long enough to reproduce.
3. The age of reproductive maturity.
4. Number of times that the individuals reproduce in a life span.
5. The life span of individuals.

Question 19

R-Selected Strategies

Answer 19

Short lifespan, early reproductive age, large broods of offspring.

Question 20

K-Selected Strategies

Answer 20

Few offspring per reproductive cycle, relatively long time to mature, invest a lot of energy into helping offspring mature.

Question 21

Protective Coloration

Answer 21

Adaptation that helps individuals avoid predation, including camouflage, mimicry, and body colors as warning signs.

Question 22

Batesian Mimicry

Answer 22

Looking like a well-defended model.

Question 23

Mullerian Mimicry

Answer 23

Two species, both unfavorable to predators in different ways looking like each other.