Chapter 15- Bio II Semester II

in a small population of birds assume 5 out out of 20 alleles are the type the code for blue feathers. what is the allele frequency of blue feather.

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The nonliving components of an environment such as weather and water are?

Abiotic components

Genetic drift tends to occur in populations that

Are small

in genetic drift allele frequencies change because of

Chance

When individuals at only one end of the bell curve or phenotype have high fitness, the result it?

Directional selection

in a population of finches in which one group has a short beak and the other has a long beak and which has occurred?

Disruptive selection

which is most likely to produce an African butterfly species in the wild whose members have one of two strikingly different color patterns.

Disruptive selection

which do biologists consider a random change

Genetic drift

Over time the movement of people has steadily increased. this has altered the course of human evolution by increasing

Gene flow

genetic differences between populations tend to be reduced by

Gene flow

which mutation would increase evolutionary fitness?

One that increases the frequency of successful reproduction

Natural selection acts directly on

Phenotypes

Population A has 10 birds, one is brown and nine are red. Population B has 100 birds of which 10 are brown. Population C has 30 birds, 3 of them are brown. which would it be least likely that an accident would significantly alter the frequency of the brown allele

Population B

the elaborate courtship displays common among animals are the result of?

Sexual selection

Sparrow with average size wings survive severe storms better than those with longer or shorter wings, illustrating

Stabilizing selection

the phenotypes for a typical polygenic trait can be expressed as

a bell-shaped curve

which is an example of assortative mating

a female mouse chooses a mate because he is the same color

Which phrase best defines evolution by natural selection?

a process of change in species over time

a population is defined as

all individuals of the same species located within a given geographic region

Which best describes the results of natural selection?

changes in the inherited characteristics of a population

as predator and prey acquire new characteristic to help them survive the constant arms race between them, what is occurring

coevolution

Mutations do not always affect an organism's genotype

false

a polygenic trait is controlled by one gene

false

in a population, the most common phenotype represents the dominant allele

false

all the genes of all the members of a particular populations?

gene pool

one similarity between natural selection and genetic drift is that both events

involve a change in population allele frequencies

Which is a true statement concerning genetic variation?

it must be present in a population before natural selection can act upon the population

which statement best summarizes evolution as it is viewed today?

it's the differential survival and reproduction of most fit phenotypes

Which will tend to produce adaptive changes in populations?

natural selection

which statement regarding natural selection is false

natural selection starts with the creation of new alleles

Within a large population if no mutation,s no migration, random matings, and each individual has an equal chance of reproduction, which will happen?

no evolution will occur

an adaptation is an inherited characteristic that can be?

physical or behavioral

Population A has 10 birds, one is brown and nine are red. Population B has 100 birds of which 10 are brown. Population C has 30 birds, 3 of them are brown. which populations is more likely to be subject to bottleneck effect

population A

the male peacock's beautiful tail is really a trade off between?

sexual selection and natural selection

natural selection changes allele frequencies because

some individuals survive and reproduce more successfully than others.

when individuals with an average form of a trait have the highest fitness, the result it?

stabilizing selection

genetic drift resulting from a disaster that drastically reduces a population size is called

the bottleneck effect

Genetic drift that follows the colonization of a new habit by a small group of individuals is called

the founder effect

which describes what all members of a population share?

they are members of the same species

which statement about gene pools is typically true?

they contain two or more alleles for each inheritable trait

Genetic drift may occur when a small group of individuals colonize

true

Natural selection on single gene traits can lead to changes in allele frequencies

true

fitness refers to an organisms's ability to survive and reproduce in a specific environment

true

in a gene pool, as the relative frequency for one allele of a trait increases, the relative frequencies of other alleles for that trait decrease

true

If a mutation introduces a new skin color in a lizard population, which might determine whether the frequency of the new allele will increase?

whether the mutation makes some lizards more fit for their environment than other lizards.