Chapter 3

Which of the following is accurate?

*Ecotourism combines wildlife conservation with economic benefits.* Any damaged ecosystem can be completely restored. Costa Rica has declared national bankruptcy because of its failed ecotourism industry. Our understanding of genetics allows us to replace extinct species. Humans can find and make their own resources if they destroy natural ecosystems.

Which of the following statements about the amoeba population described at the end of the tutorial is true?

*It is more vulnerable to extinction due to lack of genetic variation.* It is healthier than the starting population. It is less vulnerable to extinction because it survived the catastrophe.

a single fish living in the lake's shallow water near the shoreline.

Organism

a group of fish of the same species inhabiting the shallow water near the shoreline.

Population

Number of individuals within a population per unit area

Population Density

Many interacting species that live in the same area

Community

Specific environment in which an organism lives

Habitat

The sixth mass extinction event is likely being caused by __________.

large predators such as wolves and mountain lions *human-induced events* disease pandemics meteorites

The functional role of a species in its community is its ________.

selection habitat distribution *niche* place in the food chain

Which of the following would be a limiting factor for a population of dolphins in the ocean?

the number of dolphins in the population atmospheric oxygen levels rainfall *numbers of fish that dolphin prey on*

When the organisms of a particular population seek habitats or resources that are unevenly spaced, the distribution of the individuals in the population is ________.

uniform random evenly dispersed *clumped* binary

For a population with a growth rate of −3 per 1,000/year, how would you express that growth rate as a percentage?

−0.03% *−0.3%* −30% −300%

Of the following, ________ are the major factors that determine a population's growth rate.

survivorship, natural selection, mutation, and extinction immigration, climate, emigration, and population distribution limiting factors, carrying capacity, mutation rate, and inbreeding *birth rate, death rate, emigration, and immigration* adaptation, competition, birth rate, and emigration

If a population had a carrying capacity of 1000 individuals, which of the following populations would be experiencing the greatest rate of growth as a percentage of the current population size?

*a population of 10 individuals* 500 individuals 1000 individuals The answer cannot be determined.

Which of the following populations would be most vulnerable to extinction?

*a small, endemic population* a small population of generalists a large population of generalists a medium-sized population of specialists

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

*has more effect on the evolution of a small population.* causes populations to become better adapted to their environments. occurs when individuals move into or out of a population, changing the allele frequencies in the population. always increases the frequency of brown alleles in the population. has more effect on the evolution of a large population.

Which of the following is the broadest (most all-encompassing) level of ecological organization?

*the biosphere* a population a kingdom an ecosystem

Extinction is ________.

*the disappearance of a species from Earth* always caused by human disturbance something that occurs only rarely the loss of communities from the planet proceeding more slowly now than at any other time

The logistic growth curve can be said to appear similar to __________.

*the letter S* the letter X a zigzaggy letter W the letter J

Suppose you are studying a population with the following characteristics: Birth rate = 10 per 1,000/year Death rate = 12 per 1,000/year Immigration rate = 2 per 1,000/year Emigration rate = 3 per 1,000/year What is the growth rate for this population?

*−3 per 1,000/year* −1 per 1,000/year 17 per 1,000/year 27 per 1,000/year

Communities and the abiotic material with which their members interact

Ecosystem

the fishes, invertebrates, plants, microbes, rocks, sediments, and water in the lake, and the interactions between them.

Ecosystem

Species occurring in only one area

Endemic

Read the following scenario and answer the question(s) below. Between 1907 and 1923, cattle grazing in the Kaibab National forest in Arizona was greatly reduced, deer hunting was eliminated, and predators were killed. Over 600 cougars, 11 wolves (most had already been killed in the 1800s), and 3000 coyotes were trapped or shot. In response, the deer herd began to increase. By 1915, the deer were estimated at 25,000; by 1920 at 50,000; and by 1923 at approximately 100,000. What is going to happen to the area resources for deer after 1923?

The deer herd will have leveled off to a steady state, so the resources will recover. *The deer herd continues to increase, so the resources will continue to be damaged.* The deer herd will have begun decreasing, so the resources will recover. The deer herd will have leveled off to a steady state, but the resources will continue to be damaged. As the deer switch to the forage previously used by cattle, the resources will recover.

Territoriality generally results in what kind of population distribution?

aggregated *uniform* clumped random

When Darwin wrote On the Origin of Species, he knew very little about the subject of _____, an essential component of evolutionary theory today.

marine biology zoology botany *genetics*

True or False. In the example described in the tutorial, the red amoebas survived the catastrophic event, and all future generations of amoebas were red because the red amoebas had a higher reproductive rate than the blue ones.

*False*

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.* Natural selection causes the frequency of the brown allele to increase. This is an example of genetic drift. Natural selection causes the frequency of the green allele to increase. Gene flow causes the frequency of the green allele to increase.

Which of the following is true?

*Species on Earth today are but a fraction of all species that ever lived.* Bacteria represent a newer form of life, not present during the early prehistory of Earth. Extinctions of past species have always happened gradually and on a small scale. The number of species existing at one time has decreased throughout history. Most organisms present early in Earth's prehistory were more complex than modern organisms.

A species has evolved an asexual mode of reproduction by having offspring develop from unfertilized eggs. Which of the following will be true of this species' response to natural selection?

*There will be less genetic variation from sexual recombination and a risk of not adapting quickly to environmental change.* There will be more deaths from natural selection because there is no mutation. The species will compensate for loss of genetic variation by hybridizing with other species. There will be fewer deaths from natural selection because sexual recombination always leads to extinction. The species will increase in numbers because genetic variation is increased.

Which of the following is considered a community?

*several interacting species living in the same area* a single population whose individuals are similar enough to each other to be able to breed successfully all of the living and nonliving things on Earth an ecosystem

Suppose you are studying a population with the following characteristics: Birth rate = 11 per 1,000/year Death rate = 10 per 1,000/year Immigration rate = 4 per 1,000/year Emigration rate = 3 per 1,000/year What is the growth rate for this population?

0 per 1,000/year *2 per 1,000/year* 14 per 1,000/year 28 per 1,000/year

For a population with a growth rate of 2 per 1,000/year, how would you express that growth rate as a percentage?

0.02% *0.2%* 20% 200%

Suppose you are studying a population with the following characteristics: Birth rate = 14 per 1,000/year Death rate = 6 per 1,000/year Immigration rate = 5 per 1,000/year Emigration rate = 1 per 1,000/year What is the growth rate for this population?

4 per 1,000/year *12 per 1,000/year* 14 per 1,000/year 26 per 1,000/year

fishes, invertebrates, plants, and microbes inhabiting the shallow water near the shoreline.

Community

Stabilizes a population at its carrying capacity

Environmental resistance

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

Green beetles migrate out of the population, and brown beetles migrate into the population. Green beetles and brown beetles always leave the same number of offspring. A storm kills more green beetles than brown beetles by chance. Green beetles migrate out of the population. *Green beetles leave more offspring than brown beetles because they are better at finding food.*

__________ is the number of individuals in a population per unit area.

Population size *Population density* Population distribution Population dynamics

Endemic species ________.

are invasive species that cause extinction have high rates of mutations that lead to large numbers of offspring species *are found only in one place on the planet* are generalist organisms cause disease

Density-dependent factors __________.

are less important for regulating population size than density-independent factors cause decreases in numbers of species in an ecosystem as a result of temperature extremes *have a greater impact at higher population densities* act at the community level

The carrying capacity is the ________.

average number of offspring carried to term by a species greatest number of different niches possible in a given area limitation on numbers of species in a community *maximum sustainable population size that a given environment can support* potential growth in the number of species in a given area

In a population of field mice, an example of an adaptive trait that could help with reproduction and/or survival would be ________.

being brightly colored so other mice could see it spending less time searching when food is scarce *having a bit more fur to withstand cold weather* having shorter legs to be lower to the ground needing to eat more food than other mice its size

Heavy rains and mudslides cause a river to change course, isolating two groups of lizards of the same species from one another. Over a long period of time ________.

both groups will probably become native species *the groups will probably diverge genetically, and speciation may occur* one group will probably become an endemic species one or both groups will probably become invasive species one or both groups will probably emigrate

A coyote, which can alter its food intake to match seasonal abundance of plants, fruits, or small animals, is considered to be ________.

density-independent and resource neutral a clumped species a specialist, which has no niche an endemic, able to be flexible *a generalist, able to be flexible in major dimensions of its niche*

Scientists studying evolution on the Solomon Islands described which animal as the 'poster child' for the biological species concept?

frog *white-eye bird* snake sea turtle

If we ignore the effects of migration when determining population growth rates, we would calculate the population's __________, which equals __________.

growth rate; (death rate) - (birth rate) growth rate; (birth rate) - (death rate) rate of natural increase; (crude death rate) - (crude birth rate) *rate of natural increase; (birth rate) - (death rate)*

In ecology, a ________ is made up of interacting populations of different species that inhabit the same area.

guild biome *community* ecosystem population

A population is a group of ________.

individuals of several interacting species that live in one area cells that have similar function *individuals of a single species that live and interact in one area* individuals of several interacting species that interact in multiple ecosystems all individuals of a species in all locations

The fossil record clearly shows that ________.

large complex organisms evolved long before simple organisms several different species can hybridize to produce a single new species *all species evolve from pre-existing species* nearly all species that have existed in the past still exist today new species appear suddenly and fully differentiated, without an ancestral species

Where are the Solomon Islands located?

off the coast of California off the southern tip of Florida *in the South Pacific* in the Mediterranean Sea

In order for two organisms to belong to the same species, individuals of their species must __________.

share more than 30% genetic identity with each other live in the same geographical area be of the same sex *be able to reproduce and have fertile offspring*

Which of the following is an example of selective breeding (artificial selection) by humans?

the diversity of human species in the world today the great diversity of human-made fabrics the extinction of frogs in Monteverde's cloud forest *the diversity of dog breeds in the world today*

In the initial fly population prior to the isolation, it is safe to assume that ________.

the population is mating with individuals of other species there is already significant genetic divergence taking place *the population is interfertile, i.e. any male could successfully mate with any female* natural selection is not operating on the population no mutations are occurring in the population

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

this causes the population to evolve due to genetic drift. this causes the population to evolve due to gene flow. *the frequency of the green allele will increase.* the frequencies of the brown and green alleles will not change. the frequency of the brown allele will increase.

For a population with a growth rate of 12 per 1,000/year, how would you express that growth rate as a percentage?

0.12% *1.2%* 120% 1200%

Which statement below most accurately describes a phylogenetic tree?

A phylogenetic tree is a genetically modified tree that can produce asexually without using seeds. A phylogenetic tree is a branching diagram used to illustrate the steps an organism went through during artificial selection. *A phylogenetic tree is a branching diagram used to illustrate a scientist's hypothesis about how divergence took place among evolutionary lines.* A phylogenetic tree is a diagram that shows how one species develops into another.

Read the following scenario and answer the question(s) below. Between 1907 and 1923, cattle grazing in the Kaibab National forest in Arizona was greatly reduced, deer hunting was eliminated, and predators were killed. Over 600 cougars, 11 wolves (most had already been killed in the 1800s), and 3000 coyotes were trapped or shot. In response, the deer herd began to increase. By 1915, the deer were estimated at 25,000; by 1920 at 50,000; and by 1923 at approximately 100,000. Which of these graphs shows the Kaibab deer population between 1900 and 1923?

A rapidly decreasing slope from left to right. An S-shaped curve that shows a smooth, rapid increase and then levels off. A "sine wave" curving up, down, up, down. *A J-shaped upward curve with a very rapid increase.* A straight line slanting upward, showing a steady increase over time.

Based on the video, what can you infer about speciation--the process by which one species splits into two or more species?

It is rare for new species to form on islands. New species typically form as a consequence of new parasites or predators in the environment. Different species are typically very different in appearance, even if they are closely related. *Physical separation of populations is often part of the speciation process.*

Why did the biologists consider a frog that they found to be a new species?

Its coloration was different from other known frogs. *Its call was unique.* It jumped higher than other known frogs. It was larger than any known frog.

Which of the following events could NOT be caused by a population bottleneck?

Loss of alleles Changes in allele frequency Reduction in genetic variability *Increased population size*

Which of the following would protect Earth's biodiversity?

Prevent the introduction of a non-native species into an area. Preserve habitats in many countries. Encourage ecotourism. *All of the listed responses are correct.*

___________ is the only process that can change a gene's DNA and therefore give rise to new variations of the gene.

Selective breeding Natural selection *Mutation* Extirpation

An example of a density-independent factor would be ________.

a plant parasite, such as mistletoe blight (a mold disease) in a wheat field *cold weather causing a lake to freeze* suitable nest sites for a flock of warblers a specialist searching for the one species of plant that is its food

The evolution of populations due to chance is

has more effect in large populations than in small populations. gene flow. genetic variation. *genetic drift* natural selection.

Which of the following best represents the overall growth rate of a population?

immigration rate - emigration rate *(birth rate - death rate) + (immigration rate - emigration rate)* (birth rate + immigration rate) + (death rate + emigration rate) birth rate - death rate

Density-dependent factors ________.

include the effects of rainfall on an entire community include the effects of a hard freeze on an entire community include the effects of a hard freeze on a single species within a community *include the effects of disease, predators, and food on a single species within a community* cause decreases in the number of species in an ecosystem