Chapter 25- Evolutionary Processes

Question 0

Hardy-Weinberg Principle

Answer 0

A principle of population genetics stating that genotype frequencies in a large population do not change from generation to generation in the absence of evolutionary processes.

Question 1

Fitness

Answer 1

The ability of an individual to produce viable offspring relative to others of the same species.

Question 2

Null Hypothesis

Answer 2

A hypothesis that specifies what the results of an experiment will be if the main hypothesis being tested is wrong.

Question 3

Gene Pool

Answer 3

All of the alleles of all of the genes in a certain population.

Question 4

Genetic Variation

Answer 4

1) The number and relative frequency of alleles present in a particular population.

Question 5

Directional Selection

Answer 5

A pattern of natural selection that favors one extreme phenotype with the result that the average phenotype of a population changes in one direction.

Question 6

Stabilizing Selection

Answer 6

A pattern of natural selection that favors phenotypes near the middle of the range of phenotypic variation.

Question 7

Purifying Selection

Answer 7

Selection that lowers the frequency or even eliminates deleterious alleles.

Question 8

Disruptive Selection

Answer 8

A pattern of natural selection that favors extreme phenotypes at both ends of the range of phenotypic variation.

Question 9

Speciation

Answer 9

The evolution of two or more species from a single ancestral species.

Question 10

Balancing Selection

Answer 10

A pattern of natural selection in which no single allele is favored in all populations of a species at all times.

Question 11

Frequency-Dependent Selection

Answer 11

A pattern of selection in which certain alleles are favored only when they are rare.

Question 12

Genetic Drift

Answer 12

Any change in allele frequencies due to random events.

Question 13

Sampling Error

Answer 13

The accidental selection of a nonrepresentative sample from some larger population, due to chance.

Question 14

Genetic Marker

Answer 14

A genetic locus that can be identified and traced in populations by laboratory techniques or by a distinctive visible phenotype.

Question 15

Founder Effect

Answer 15

A change in allele frequencies that often occurs when a new population is established from a small group of individuals.

Question 16

Genetic Bottleneck

Answer 16

A reduction in allele diversity resulting from a sudden reduction in the size of a large population, due to a random event.

Question 17

Population Bottleneck

Answer 17

A sudden reduction in the size of a large population.

Question 18

Gene Flow

Answer 18

The movement of alleles between populations.

Question 19

Migration

Answer 19

The movement of individuals from one population to another.

Question 20

Mutation

Answer 20

Any chanhe in the hereditary material of an organism.

Question 21

Deleterious allele

Answer 21

An allele that reduces an individual’s fitness.

Question 22

Inbreeding

Answer 22

Mating between closely related individuals.

Question 23

Inbreeding Depression

Answer 23

In inbred offspring, fitness declines due to deleterious recessive alleles that are homozygous.

Question 24

Heterozygote Advantage

Answer 24

A pattern of natural selection that favors heterozygotes over homozygotes.

Question 25

Loss-Of-Function Mutation

Answer 25

A mutant allele that does not function at all.

Question 26

Sexual Selection

Answer 26

A pattern of natural selection that favors individuals with traits that increase their ability to obtain mates.

Question 27

Parental Care

Answer 27

Any action by which an animal expends energy or assumes risks to benefit its offspring.

Question 28

Territory

Answer 28

An area that is actively defended by an animal from others of its species.

Question 29

Sexual Dimorphism

Answer 29

Any trait that differs between males and females.

Question 30

Genotype Frequency

Answer 30

The frequency of a genotype in a population.

Question 31

Countervailing Selection

Answer 31

One cause of directional selection on a trait is counterbalanced by a different factor that causes selection in the opposite direction.

Question 32

Polygenic Trait

Answer 32

A trait controlled by multiple alleles.

Question 33

Nonrandom Mating

Answer 33

When mates are chosen based on traits rather than at random.

Question 34

Homozygousity

Answer 34

The number/frequency of homozygous individuals/genes.

Question 35

Fundamental Asymmetry of Sex

Answer 35

Frmales invest much more in their offspring than do males.

Question 36

Female Choice

Answer 36

The choice of a female to mate with the healthiest or more fit males.

Question 37

Male-Male competition

Answer 37

The competition between males over mates.

Question 38

Investment

Answer 38

What females give initially to the care of offspring.