Biology - Chapter 16: How Populations Evolve

A type of mating that occurs when individuals choose a mate with a preferred trait is called ______ mating.

Assortative

Gonorrhea is becoming more difficult to treat because antibiotic resistance is developing in the ______ that causes gonorrhea.

Bacterium

Which of the following are types of genetic drift?

- Bottleneck effect - Founder effect

Which of the following are conditions that a population must meet in order to maintain Hardy-Weinberg principle?

- No selection - No mutation - No genetic drift - No new members can join the population and no existing members can leave

Calculate the homozygous recessive genotype frequency if the recessive allele frequency is 0.4.

0.16

Assuming Hardy-Weinberg equilibrium, what will the frequency of the homozygous dominant genotype be in the next generation if the frequency of the dominant allele in the current generation is 0.60? 0.60 squared

0.36

What is the frequency of the recessive allele in a population if 16% of the individuals in the population have the recessive phenotype? Frequency of the recessive allele = square root of 0.16

0.40

What is the frequency of a recessive allele in a population if 25% of the individuals are homozygous recessive and 50% are heterozygous? Frequency of the recessive allele = square root of 0.25

0.50

Calculate the dominant allele frequency if the dominant genotype frequency is 30% and the heterozygous genotype frequency is 50%? Square root of 0.30

0.55

Calculate the dominant allele frequency in a population if the homozygous dominant genotype frequency is 49%.

0.7

It is estimated that a mutation occurs once in every _____ cell divisions.

100,000

Identify the population that has the greatest chance of becoming reproductively isolated over time.

6 katydids in an isolated prairie

The bottleneck effect is the loss of genetic diversity that can be caused by ______.

A natural disaster

Natural selection favors the phenotype that is most _________.

Adaptive

Gene flow causes microevolution by introducing new or rare _____ into a population.

Alleles

When an extreme phenotype is favored and the distribution curve moves toward that extreme, this would demonstrate a type of natural selection called ____________ selection.

Directional

The maintenance of two extreme phenotypes within a population in an environment that is subject to change results from __________ selection.

Disruptive

Which type of selection is most likely to persist in an environment that is subject to a high degree of change?

Disruptive

Populations that have a structure in which higher-ranking animals have greater access to resources than lower-ranking animals are said to have _______ hierarchies.

Dominance

What can genetic drift eventually lead to?

Evolutionary change

The ability of an organism to produce surviving offspring, compared to the other members of a population is called ____________.

Fitness

A type of genetic drift, in which a small population isolates itself from the main population, causing the gene frequencies to differ is known as the ______________ effect.

Founder

A type of genetic drift in which a small number of individuals form a new population away from the original one is called the ______.

Founder effect

What does p represent in the Hardy-Weinberg principle?

Frequency of the dominant allele

Population genetics studies the diversity of a population at the level of the ________.

Gene

A Canada goose leaving it's population in order to mate with a goose from another population is an example of _______ ________.

Gene Flow

The movement of alleles between populations is referred to as ______.

Gene flow

All of the alleles of all of the genes in a population is known as the _______.

Gene pool

Gene flow is the movement of ________ between populations.

Genes

The bottleneck effect is a type of ______.

Genetic drift

When chance causes only certain members of a population to reproduce and pass on their alleles to the next generation it is called ___________ ____________.

Genetic drift

Assortative mating can cause the frequency of _____ to change within a population.

Genotypes

The hypothesis regarding sexual selection that states that females choose mates on the basis of traits that increase a male's chance of survival is called the _____ hypothesis.

Good genes

Which genotype is most prevalent in regions of Africa that have high rates of malaria?

Hb^A Hb^S

Individuals who have a genetic advantage that prevents them from dying from sickle-cell disease and malaria are said to have a _______ advantage.

Heterozygous

Which allele combination will help maintain genetic diversity within the population?

Hh

Identify why certain traits are not perfect.

Imperfections are a compromise for beneficial traits.

Variation within a population is important because

It increases the populations chances of survival in changing environmental conditions.

Regions of Africa, in which populations have high frequencies of the sickle cell allele, will have high rates of _______ in their environments.

Malaria

The alleles in nonrandom mating assort according to ______.

Mating behavior

Male baboons at the top of a dominance hierarchy benefit by _____.

Monopolizing fertile females

Chemical or physical agents that cause mutation are called ____________.

Mutagens

The raw material for evolutionary change, which introduces new variations among members of a population is caused by _______.

Mutation

Assortative mating is a type of ______ mating in which an individual is chosen because of a preferred trait.

Nonrandom

When individuals mate based upon preferences it is known as ____________ mating.

Nonrandom

If a trait is controlled by more than one gene, the trait is referred to as being ______.

Polygenic

A group of organisms of a single species living in the same geographic area is called a _____________.

Population

All of the western blue birds living in a 100 hectare forest would be an example of a(n) ______.

Population

Microevolution refers to evolutionary changes within a ___________.

Population

If migration between populations does not occur, the gene pools of those populations may become different over time which can lead to the populations becoming ___________ isolated.

Reproductively

The hypothesis regarding sexual selection that states that females choose mates on the basis of appearance is called the _____ hypothesis.

Runaway

The adaptive changes in males and females that lead to an increased ability to secure a mate is called __________ selection.

Sexual

An abnormal form of hemoglobin causes _______-_______ disease.

Sickle cell

A selection type that has a large peak in the center of the range of distribution is called

Stabilizing

The heterozygote advantage regarding sickle-cell disease is an example of _________ selection.

Stabilizing

The intermediate phenotype is the favored phenotype in ____________ selection.

Stabilizing

Which form of selection is thought to be responsible for keeping the cystic fibrosis allele in a population?

Stabilizing

Match the form of natural selection with the correct description.

Stabilizing - Occurs when an intermediate phenotype is the most adaptive for the given environmental conditions. Directional - Occurs when an extreme phenotype is favored, and the distribution curve shifts toward one of the extremes. Disruptive - Found when two or more extreme phenotypes are favored over the intermediate phenotype.

The defensive behavior necessary to defend a territory is called _______________.

Territoriality

The area that is defended against competitors is called a _____________.

Territory

Sexual dimorphism means ______.

That females and males differ in size and other traits

What will happen to the genotype frequencies of a population if assortative mating takes place?

The frequencies will change

The allele frequency is ______.

The percentage of each allele in a population

A gene pool includes all of the ____________ of all of the genes of a species.

alleles

According to cost-benefit analysis, the ______ of partaking in a particular behavior or strategy must outweigh the ______.

benefit, cost

No mutations, no migration, random mating, no selection, and a large gene pool are required to maintain Hardy-Weinberg ______________.

equilibrium

The percentage of each allele in a population's gene pool is referred to as an allele _____________.

frequency

If a scientist studies the diversity of genes in a population they are studying population ____________.

genetics

The maintenance of genetic diversity of future generations is often maintained through the _____________ advantage.

heterozygote

The heterozygote advantage means that the heterozygote for a trait has an advantage over the two _____________.

homozygotes

Which equation describes the genotype frequencies of a non-evolving population?

p^2 + 2pq + q^2

A trait that is controlled by many genes is said to be a _________ trait.

polygenic

Sexual selection in males usually results in an increased ability to __________ for mates, whereas sexual selection in females usually involves _____________ a mate with the best fitness.

Compete; Selecting

Mutations serve as a source of new genetic variation and are caused by changes to an organisms ___________ sequence.

DNA

Sexual selection in _____ usually results in an increased ability to compete for mates, whereas sexual selection in _____ usually involves selecting a mate with the best fitness.

males; females