Biology Mastering Biology Ch. 13,14,15,16,17

Suppose that, with regard to a particular genetic locus for which there are only two alleles, A and a in a large population, we know that 60% of the alleles in the gene pool are A. Suppose further that we observe this population for five generations, during which we know that no mutation, selection, or migration has occurred. After this period, the frequency of the a allele is expected to be __________.

0.4

Approximately 1 out of every 2,500 Caucasians in the United States is born with the recessive disease cystic fibrosis. According to the Hardy-Weinberg equilibrium equation, approximately how many people are carriers?

1 in 25

Microevolution

A change in a population's gene pool over a succession of generations.

Sexual Selection

A form of natural selection in which individuals with certain characteristics are more likely than other individuals to obtain mates.

Population

A group of interacting individuals belonging to one species and living in the same geographic area at the same time.

Each of us is part of the ongoing evolution of the human species. Which of the following occurrences would have the greatest impact on the future biological evolution of the human population?

A mutation occurs in one of your sperm or egg cells.

Natural Selection

A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics; unequal reproductive success.

Paleontologist

A scientist who studies fossils.

Vestigial Structure

A structure of marginal, if any, importance to an organism. Vestigial structures are historical remnants fo structures that had important functions in ancestors.

Domain

A taxonomic category above the kingdom level. The three domains of life are Archaea, Bacteria, and Eukarya.

Theory

A widely accepted explanatory idea that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence

Gene pool

All the alleles for all the genes in a population at any one time.

Evolution

Descent with modification; genetic change in a population or species or generations; the heritable changes that have produced Earth's diversity of organisms.

Sexual Dimorphism

Distinction in appearance based on secondary sexual characteristics, noticeable differences non directly associated with reproduction or survival

Which of the following statements about early ideas of evolution is true?

Fossil discoveries in the early 1800s convinced many naturalists that species are not fixed and can change over time.

Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct?

Gene flow causes the frequency of the brown allele to increase.

The evolution of populations due to chance is

Genetic Drift

Bottleneck Effect

Genetic drift resulting from a drastic reduction in population size. Typically, the surviving population is no longer genetically representative of the parent population

Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection?

Green beetles leave more offspring than brown beetles because they are better at finding food.

Kingdom

In classification, the broad taxonomic category above phylum.

Phylum

In classification, the taxonomic category above class. Members of a phylum all have a similar general body plan.

Order

In classification, the taxonomic category above family.

Family

In classification, the taxonomic category above genus.

Class

In classification, the taxonomic category above order.

Genus

In classification, the taxonomic category above species; the first part of a species' binomial' for example, homo.

Evolutionary Adaptation

Modification resulting from natural selection that suits organisms to their environment.

"Natural selection" and "evolution" are two terms that are sometimes confused, even by freshman biology students. What is the relation between natural selection and evolution?

Natural selection is one of several mechanisms of evolution.

Disruptive Selection

Natural selection that favors extreme over intermediate phenotypes.

Stabilizing Selection

Natural selection that favors intermediate variants by acting against extreme phenotypes.

If an insecticide killed all of the insect pests in a particular population, could insecticide resistance evolve in this insect population?

No, because there are no remaining insects in this population to pass on beneficial alleles to the next generation.

Why is it that isolated islands, such as the Hawaiian islands, often have many endemic organisms (found nowhere else)?

Organisms evolve in isolation because of the difficulty of genetic exchange with other populations in distant locations.

According to current evolutionary theory, which of the following is true?

Populations are the units of evolution.

Which of the following is a true statement?

Species with nucleotide sequences that match closely share a common ancestor.

Taxonomy

The branch of biology concerned with identifying, naming, and classifying species.

Hardy-Weinberg Equilibrium

The condition describing a non evolving population (one that is in genetic equilibrium.

Relative Fitness

The contribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals in the population.

Artificial Selection

The selective breeding of domesticated plants and animals to promote the occurrence of desirable traits in the offspring.

Molecular Biology

The study of the molecular basis of heredity.

If a population is in Hardy-Weinberg equilibrium and remains in equilibrium, which of the following will be true?

There will be no mutations.

Evolutionary Tree

a branching diagram that reflects a hypothesis about evolutionary relationships between groups of organisms.

Binomial

a two-part Latinized name of a species; for example, Homo sapiens

If members of a population have traits that are both heritable and variable among individuals, then __________.

advantageous traits may become more widespread in subsequent generations

All known organisms translate genetic information to protein molecules via the same genetic code. This finding strongly supports the hypothesis that __________.

all organisms are descended from a single common ancestor

In evolutionary terms, an organism's Darwinian fitness is measured by its __________.

contribution to the gene pool of the next generation

Evolution of antibiotic resistance in bacteria is an example of which of the following?

directional selection

A population of squirrels is preyed on by small hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in the area tend to be very small or very large. What process is responsible for this outcome?

disruptive selection

An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms, such as hummingbirds, humans, and whales, have similar skeletal structures. This most directly suggested to biologists that __________.

dissimilar organisms might have evolved from a distant, common ancestor

The relationship of the genome to an organism is the same as that of the _____ to a population.

gene pool

homology

genetic drift

In a population with brown and green alleles for color, genetic drift

has more effect on the evolution of a small population.

The severe reduction in genetic variability seen in the endangered cheetah is probably attributable to __________.

having gone through at least one bottleneck

When they were first sold, aerosol insecticides were highly effective in killing flies and mosquitoes. Today, some 30 years later, a much smaller proportion of these insects die when sprayed. The reason fewer insects are being killed is that __________.

many mosquitoes today are descendants of mosquitoes with insecticide-resistant characteristics

The processes of __________ and __________ generate variation, and _________ produces adaptation to the environment.

mutation; sexual reproduction; natural selection

"Differential success in reproduction associated with different inherited traits" is just another way of saying __________.

natural selection

A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than individuals with other characteristics is called _____.

natural selection

Sexual selection is a form of __________.

natural selection

Directional Selection

natural selection that acts in favor of the individuals at one end of a phenotypic range

fossil record

ordered sequence of fossil s as they appear in the rock layers, marking the passage of geologic time

Birds with average-sized wings survived a severe storm more successfully than other birds in the same population with longer or shorter wings. This illustrates __________.

stabilizing selection

To help prevent the proliferation of antibiotic-resistant bacteria, you should __________.

take the full course of any antibiotics your doctor has prescribed

The population of American bison used to number in the millions of animals. Hunting and other problems greatly decreased the number of bison to about 1,000 animals. Today, the numbers are recovering to estimates of more than 200,000 animals. This crash in the population of bison and recent recovery is an example of __________.

the bottleneck effect

Which of the following is the most recent example of an evolutionary change in populations?

the development of pesticide-resistant insects

Which of the following is an example of natural selection that has been seen in our lifetime?

the evolution of antibiotic-resistant bacteria

Imagine that a new population of humans is established on a new planet from ten randomly selected people in your biology class. Over thousands of years, the descendants of those ten people reproduce and prosper, but do not reflect well the diversity of humans on Earth. This change in the diversity of people on the new planet is an example of _____.

the founder effect

If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles,

the frequency of the green allele will increase

Gene FLow

the gain or loss of alleles from a population by the movement of individuals or gametes into or out of the population.

The evolutionary effects of genetic drift are greatest when __________.

the population size is small

As a mechanism of evolution, natural selection can be most closely equated with __________.

unequal reproductive success.