Biological Diversity Chp. 49, 51, 52, 53 Study Module Questions

Which of the following statements describes a response of predators to prey?

A species of fish hides in a hole until another fish swims past that it can attack and eat. Predators use many different methods to attack prey, including hiding and laying in wait to conduct a surprise attack. To avoid predators, prey often usr a variety of anti-predator tactics, such as crypsis, mimicry, or attacking back. Moose kicking wolves is an example of prey defending themselves. Mimicry is a form of prey defense. A species of fish adopting the appearance of its surroundings is exhibiting cryptic coloration.

What percentage of the Earth's net primary productivity (NPP) is estimated to be used or prevented by humans?

2

In July 2008, the United States had a population of approximately 302 million people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88 percent?

304.7 million

In 2008, the population of New Zealand was approximately 4,275,000 people. If the birth rate was 14 births for every 1,000 people, approximately how many births occurred in New Zealand in 2008?

6 A birth rate of 14 births for every 1,000 people is the same as 14,000 births for every 1,000,000 people. The population was 4.275 million people, so the number of births was: (14,000 births per 1,000,000 people) × (4.275 million people) = 59,850 births, or approximately 60,000 births. For 6,000 births to have occurred, the birth rate would have to be 1.4 births per 1000 people. A population of 4,275,000 represents 4,275 groups of 1000 people. This value would have to be multiplied by the birth rate per 1000 people to give the number of births.

A(n) __________ distribution pattern occurs when resources are patchy.

Clumped A clumped distribution pattern occurs if the organisms associate in social groups (such as schools of fish) or if the quality of the habitat is patchy. Organisms distribute evenly or uniformly to minimize competition. Random distribution occurs when the dispersal of seeds, gametes, or larvae varies as a result of wind or currents.

Birds that follow moving ants in tropical forests benefit by catching prey that jumps out of the ants' path. The ants are unaffected by the birds' behavior. This interaction is an example of __________.

Commensalim

Which organisms would be found in the same trophic level?

Crickets and cows

Which of the following is a factor that is used to calculate population growth?

Death rate In its simplest form, population growth is the birth rate minus the death rate. The other listed factors relate to one or the other of these two primary factors.

Different aquatic biomes are distinguished by __________.

Depth of water and rate of water movement Water biomes are often differentiated by the depth of water and rate of water movement. These factors influence the number and types of species that occur there. Depth also influences the availability of light. Precipitation is not significant to aquatic environment type because it is already in water.

Which of the following statements best describes why there is seasonality in climate?

Earth is tilted on its axis, thus changing the amount of sunlight energy received by a regions north and south of the equator during the year. There is seasonality in climate because Earth is tilted on its axis, thus changing the amount of sunlight energy received by a specific place on the planet during the year. Earth's tilt, and not the sun's, is the cause of seasonality. This explains why the equator does not exhibit much in terms of seasons; there is little effect of tilt there. There are mountains in the tropics, which goes against the notion that they are a primary cause of seasonality, as well as the fact that in areas where there are no mountains, such as the Great Plains, there are wide-ranging seasonal effects. Changes in monthly temperature are a characteristic of seasonality, so temperature cannot be described as a cause.

Which of the following parasites lives on the outside of its host?

Ectoparasite

Which example supports Frederick Clements's view that biological communities are stable, integrated, and orderly entities with a predictable composition?

Following a disturbance such as a fire, certain plants succeed in growing again before other plants. Following a disturbance such as a fire, certain plants succeed in growing again before other plants. This example supports Clements's view that biological communities are stable, integrated, and orderly entities with a predictable composition. Clements championed the concept of succession, the idea that communities evolve and develop in an orderly and predictable manner. For instance, if a fire wiped out an area, one would expect to see small, fast-growing plants establish themselves quickly and then eventually be replaced by larger trees.

Which of the following environmental challenges has so far not shown a slowdown, partial recovery, or significant recovery?

Global warming has so far not shown a slowdown, partial recovery, or significant recovery. Regulatory measures taken by the United States and other countries have contributed to at least a slowdown in, if not significant recovery for, phosphate pollution, acid rain, and ozone depletion. The primary concern that has not been adequately addressed is global climate change.

Water at the source of a stream has which of the following characteristics?

H

Why does the 2009 U.S. population continue to grow even though the United States has essentially established a zero population growth (ZPG)?

Immigration The U.S. population continues to grow due to immigration. If more people immigrate to the country than emigrate out of it, the population will continue to grow despite a zero population growth (ZPG). Increased emigration would result in a population decrease and not an increase. In general, baby boomers (those born between 1946 and 1964) are no longer reproductively active, and so do not contribute to population growth. A difficult economic period might decrease population growth if affected individuals opted to have smaller families, but it would not be expected to increase the population.

What is true of the theory of island biogeography?

Immigration rates should be lower on small islands far from land than on large islands close to land.

Which of the following statements about food webs is true?

In a food web, several species can be present in each trophic level. Food webs are diagrams that demonstrate the feeding relationships among species in a particular ecosystem. These do not indicate keystone species per se or track the demographics of a particular species. They are more complex than food chains and will designate several species to each trophic level. These trophic levels seldom exceed five levels, though, because of constraints in energy transfer through the web.

Which of the following statements is true of biomagnification?

In biomagnification, the concentration of toxin can more than double at each level of the food chain. Biomagnification occurs when contaminants are bioconcentrated and then moved up the food chain to higher trophic levels. Because consumers eat so many of their resources, any contaminants present in them will magnify significantly and be concentrated in the consumer. Contaminants that are more readily excreted do not bioconcentrate and, therefore, are not as significant a problem. Biomagnification occurs across aquatic and terrestrial environments and can pose significant issues for top predators that are essential to their ecosystem, causing major environmental issues.

From its roots, garlic mustard secretes chemicals that inhibit the growth of other plant species. If, over time, other plants evolve defenses to resist the toxic chemical, and the garlic mustard becomes more toxic, then __________ has occurred.

In many parts of North America, Alliaria petiolata (garlic mustard) is an invasive plant species. From its roots, garlic mustard secretes chemicals that inhibit the growth of other plant species. If, over time, other plants evolve defenses to resist the toxic chemical, then coevolution has occurred. Coevolution is a pattern of evolution in which two species influence each other's adaptations over time. Because the example features different species, it cannot be described as intraspecific. This examples shows a competitive relationship; therefore, it cannot be considered a mutualism. This is also not an example of succession because there is not a disturbance causing the removal of organisms.

Which of the following statements about biogeochemical cycles is true?

If a plant dies, the nutrients and the plant biomass become plant litter. Litter consists of dead and decaying organisms, which are important to the biogeochemical cycle. Animals consume plant tissue, thus gaining many of the nutrients the plants received from the soil. Animals also contribute to this nutrient base while alive via defecation and shedding of hair and skin. Nutrients can move up the trophic levels when one organism consumes another.

If the Sun were to suddenly stop providing energy to Earth, most ecosystems would vanish. Which of the following ecosystems would likely survive the longest after this hypothetical disaster?

If the Sun were to suddenly stop providing energy to Earth, most ecosystems would vanish. The benthic ocean would likely survive the longest after this hypothetical disaster. The benthos of the ocean receives very little sunlight because it exists beyond the photic zone. Therefore, the lack of sunlight would hypothetically alter this ecosystem the least. Undoubtedly, there would still be a major impact to this ecosystem despite the lack of direct exposure because many resources enter this ecosystem from regions where sunlight would be important. Deserts, grasslands, tundra, and tropical rain forests all depend on the Sun's energy for primary production.

Why is Glacier Bay, Alaska, an important site for studying succession?

In the past 200 years, glaciers have retreated approximately 100 km, exposing extensive tracts of barren glacial sediments to colonization.

Which of the following statements describes an abiotic factor that may limit the geographic distribution of a species?

In warm winters, Carolina wrens are able to expand their range to northern states, but in cold winters, their range contracts to the south. An example of an abiotic factor that may limit the geographic distribution of a species is that in warm winters, Carolina wrens are able to expand their range to northern states, but in cold winters, their range contracts to the south. The abiotic factor here is temperature. Expanding a range to the north during warmer winters would be a response to an abiotic factor. The other answers all consist of responses to biotic (or living) factors.

How does net primary productivity (NPP) differ from gross primary productivity (GPP)?

NPP is the amount of energy available for primary consumers, whereas GPP is the amount of energy produced by plants and other producers. NPP is net primary productivity, whereas GPP is gross primary productivity. Gross refers to a total amount, whereas net is the amount remaining. In this context, GPP is the total amount of energy available, whereas NPP is what is made available by producers such as plants. NPP and GPP are affected by climate, as well as by the attributes of the species producing energy.

Which of the following statements describes a situation that would be studied by a researcher interested in population ecology?

Only a few salmon offspring return to the stream of their birth to breed. A situation that would be studied by a researcher interested in population ecology would occur when only a few salmon offspring return to the stream of their birth to breed. Population ecology focuses on the number and distribution of individuals over time. The measure of how many offspring are returning to a population would be of strong interest to a population biologist. Alterations to oxygen absorption would be of interest to an organismal ecologist. Predation would be a focus in community ecology, and nutrient flow would be a focus in ecosystem ecology.

Which of the following statements about freshwater environments is true?

Organisms that consume detritus are common in the benthic zones of lakes and ponds. In freshwater environments, it is true that organisms that consume detritus are common in the benthic zones of lakes and ponds. The benthic zone is the bottom or floor of an aquatic environment. Detritus falls to this area, so organisms that consume detritus can be found here. Oxygen level is not a factor that determines zones in lakes. Bogs are known for their stagnant water and are not the most productive of the wetland habitats.

What type of spatial distribution pattern would be caused by variation in the dispersal of seeds, gametes, or larvae by wind or currents?

Random distribution The distribution of seeds, gametes, or larvae is an example of random distribution because of the variation in factors such as wind and currents. A clumped distribution occurs when resources are patchy, or when organisms associate closely.. A uniform or even distribution means that the organisms are spaced to minimize competition..

According to the figure, which of the following biomes yields the highest total net primary productivity (NPP)?

The open ocean has the highest total net primary production (NPP) because it covers such a large area of the Earth. Per unit area is has a very low average NPP unlike coral reefs and algal beds, which have the highest NPP per area but make up a very small amount of area on the planet. Tropical wet forests do have a high NPP per unit and do make up 3%-4% of the Earth's area, thereby giving them a close second in overall NPP. This highlights the critical importance of this biome for NPP. Wetlands are also highly productive but make up less than 1% of the Earth's surface. Some of this is because of their conversion from wetland to agriculture and other land uses via draining of the wetlands.

Which of the following statements about exponential growth is true?

The per capita rate of increase, r, is an estimate of the number of births minus the number of deaths Exponential growth is represented by the formula dN/dt = rN; r represents the per capita rate of increase or the number of births minus the number of deaths. This type of growth does not contain a carrying capacity term, so growth of the population is not limited at any particular population size (N).

Of the many links in a nutrient cycle, which one most often limits the overall rate at which nutrients move through an ecosystem?

Typically the most time-limiting step in most systems is the decomposition of detritus. Typically there is a great deal of material to decompose, but much of it is not easily broken down. Until decomposition occurs, nutrients stay tied up in intact tissues. Once nutrients are available in the soil, they can be easily taken up by plants and converted to tissue. This tissue can then also be readily consumed by herbivores and converted to animal tissues. Because death regularly occurs, both of these tissue types continually contribute to the dead biomass.

Which of the following would take place for a species of barnacle if defenses are inducible?

Shell thickness and attachment strength increase in areas of high predation. Shell thickness and attachment strength would increase in areas of high predation if defenses are inducible. Barnacles are quite sedentary. In their adult form, their primary defenses are shell thickness and attachment strength. Both of these would increase in regions of high predation.

Two different sites contain a variety of tree species. Site one has 202 tree species, while a same-size plot at site two has 12 tree species. Which of the following is most likely to be true?

Site one is in a tropical rain forest, and site two is in a temperate deciduous forest. Site one (202 species) is in a tropical rain forest, and site two (12 species) is in a temperate deciduous forest. Tropical rain forests are known for their high biodiversity, whereas there is a much lower rate of diversity in temperate deciduous and boreal forests.

Which of the following biomes is correctly paired with the description of its climate?

Tropical forests: nearly constant day length and temperature Tropical forests: nearly constant day length and temperature is correctly paired. The tropics are known for their constant day lengths and temperatures because of their proximity to the equator. Tundras have very short summers and harsh winters. Temperate forests do not have a short growing season and can have very cold winters. Temperate grasslands have cold winters.

Suppose that the number of bird species is determined mainly by the amount of variety found in the environment. If so, in which of the following biomes would the greatest number of bird species be found?

Tropical rain forest Of the forested biomes, tropical rain forests have by far the highest abundance and diversity of trees. Savannas and grasslands have very few trees, and deserts often have no trees at all.

Which of the following is an example of Müllerian mimicry?

Two species of unpalatable butterfly that have the same color pattern is an example of Müllerian mimicry. Müllerian mimicry is often confused with Batesian mimicry. In Müllerian mimicry, species appear similar to one another because both share a common trait, such as unpalatability. In Batesian mimicry, one of the species does not possess that trait (e.g., harmful sting) but looks like a species that does. The nonpoisonous frog mimicking a poison dart frog, the nonvenomous snake rattling its tail like a rattlesnake, and even the moths' spots looking like owls' eyes are examples of Batesian mimicry. Mimicry can also be confused with cryptic coloration. Cryptic coloration and object resemblance are the "mimicking" of a particular background to remain hidden, such as that observed in a chameleon that changes its skin pigmentation to resemble a dead leaf.

Imagine some terrible disease that strikes and kills great numbers of children but has limited effects on adults. If such a disease were to afflict human populations, what type of survivorship curve would you expect to see four our species?

Type III A population that shows dramatic mortality early in life with much lower mortality later shows a Type III survivorship curve. This pattern is seen in organisms that produce many offspring, most of which do not survive. A Type I survivorship curve is the sort seen for human populations in developed countries. Mortality remains relatively low until late in life. A Type II population curve shows roughly equal mortality at all ages. There is no Type IV survivorship curve.

A carp has a large number of offspring, but predators eat many of them during the first year of life. Once they survive to maturity, they have few predators. What type of survivor ship curve does a carp have and why?

Type III, because carp have a low survivor ship initially but a high survivor ship once they have matured The carp survivorship curve is type III because carp have a low survivorship initially but a high survivorship once they have matured. Type I curves display the opposite trend. Type II curves have steady survivorship throughout their lives.

Which of the following best describes resource partitioning?

Slight variations in a niche that allow similar species to coexist Slight variations in niche that allow similar species to coexist best describes resource partitioning. Resource partitioning is differential resource utilization that allows similar species to coexist. This can often result in an increase in species diversity because it allows species that might normally share an identical niche to coexist. Although species can coevolve, the competitive exclusion principle indicates that two species with identical niches will not coexist in nature. Resource partitioning allows for more species to coexist by reducing competition; this eliminates a clear winner. Niche partitioning may be observed in a climax community; it is not a stage of succession.

What are the implications of the fact that hare populations increase most when food availability is high and predators (lynx) are excluded?

The hare population is controlled by both food supply and the lynx population. f the hare population increases most when food is high and predators are excluded, then the hare population is likely controlled by both food supply and the lynx population. Hare populations are impacted by lynx predators, yet the populations also respond to increases in resource availability. Therefore, when food availability is high and predators are excluded, the population will greatly increase.›

If you study the interactions between cheetahs and the Thomson's gazelles they prey upon, you would primarily be doing __________ ecology.

community

Why are natural lakes and ponds more common at higher latitudes?

Because the scouring action of past glaciers formed large depressions in the landscape. Natural lakes and ponds are more common at higher latitudes because the scouring action of past glaciers formed large depressions in the landscape. The primary reason for the large number of lakes and ponds at higher latitudes is that glaciers occurred in the past at these latitudes. Ice dams would not occur every winter in a large number of lakes. Higher precipitation actually occurs at the equator than at higher latitudes. Beaver dams might cause more ponds, but they are too small to cause lakes to form.

Invertebrates and fish that eat dead organic matter will be most abundant in the _________ of freshwater lakes.

Benthic zone Organisms are adapted to certain zones. For example, cyanobacteria and algae—and animals that eat them—are abundant in the photic zone. Invertebrates and fish that eat dead organic matter are abundant in the benthic zone of freshwater lakes. Intertidal and neritic zones are found in marine ecosystems.

Which of the following would be a example of a population?

Births Increased number of births will clearly add to population growth, whereas increased death and emigration will reduce population growth. A lack of immigration means that fewer individuals from outside the population are moving in. This would also translate to lower growth rates.

What is the difference between logistic and exponential growth model predictions when population numbers become high?

Both models are the same at low population densities, but when densities are high, growth is reduced or stopped in the logistic model, whereas growth continues in the exponential model regardless of population density.

What are population dynamics?

Changes in populations through time and space Population dynamics refer to changes in populations through time and space. Regular fluctuations in population size are an example of potential population dynamics but are not a definition of it. The other two examples describe factors at a particular moment in time.

Why are changes in the global carbon cycle important?

Changes in the global carbon cycle are important because carbon dioxide is a greenhouse gas. The conversion of carbon to carbon dioxide (CO2) has severe consequences in global climate change because the increase in CO2 is associated with increases in temperature across Earth's history. Although there are other factors that can affect Earth's climate, this one is the most significant (and avoidable).

Which of the following has (have) been presented as a cause for sudden irreversible shifts, such as those seen in a forested area converting to a grassland?

Climate change, forest fires, and invasive grasses Factors sometimes combine in ways that cause a "tipping point" to occur, a sudden shift in the ecosystem that is not reversible, such as the sudden shift of a forest to a grassland as a result of the combined effects of climate change, forest fires, and invasive grasses. Understanding the complex interactions of biotic and abiotic factors in ecosystems—and predicting future changes—is among the most challenging and important tasks that ecologists face today.

The energy invested in the production of new tissue by autotrophic organisms is __________.

net primary productivity The energy invested in the production of new tissue by autotrophic organisms is net primary productivity. Productivity is a measure of energy flow through biotic systems. Part of the energy is converted to tissue. The total amount of chemical energy produced in a given area and time period is gross primary productivity (GPP), whereas net primary productivity (NPP) is the energy incorporated into the producers themselves. Maintenance uses energy, increasing the difference between NPP and GPP.

The combination of conditions that a species can tolerate in the presence of competitors is a __________.

realized niche The combination of conditions that a species can tolerate in the presence of competitors is a realized niche. By contrast, a fundamental niche is the combination of conditions a species can theoretically use. This compartmentalizing of resources in a habitat is known as niche differentiation and is used to reduce competitive interactions that result from any overlap.

A population is a __________.

group of individuals from the same species that live in the same area at the same time A population is a group of individuals from the same species that live in the same area at the same time. The definition of species is individuals that are able to interbreed and produce viable offspring. A community is a group of individuals from different species that live in the same area at the same time.

The __________ of water is an important determinant of light penetration.

turbidity The turbidity, or cloudiness, of water is an important determinant of light penetration. The amount of salt and oxygen concentration do not affect light penetration. Adhesiveness is a property of water as it is attracted to other materials.

The main cause of the increase in the amount of carbon dioxide in Earth's atmosphere over the past 150 years is __________.

the burning of larger amounts of wood and fossil fuels.

In an interaction between two species, removal of either species results in decreased fitness of the other species. What kind of interaction do these species normally have?

Mutualism

Which statements about dispersal are correct? 1. Dispersal is a common component of the life cycles of plants and animals. 2. Colonization of devastated areas after floods or volcanic eruptions primarily depends upon levels of carbon dioxide in the environment. 3. Seeds are important dispersal stages in the life cycles of most flowering plants. 4. Dispersal occurs only on an evolutionary time scale.

1 and 3 Statements 1 and 3 about dispersal are correct: Dispersal is a common component of the life cycles of plants and animals, and seeds are important dispersal stages in the life cycles of most flowering plants. Dispersal exists commonly in both plants and animals. For flowering plants, dispersal most often occurs during the seed stage, where they are easily transported great distances. This happens every year and so is not on an evolutionary time scale, which assumes long periods of time for an event to occur. Dispersal events, and not climate, are important in the colonization of highly disturbed areas.

Which of the following assumptions have to be made regarding a mark-recapture estimate of population size? 1. Marked and unmarked individuals have the same probability of being trapped. 2. The marked individuals have thoroughly mixed with the population after being marked. 3. No individuals have entered or left the population by immigration or emigration.

1, 2, and 3 1, 2, and 3 are correct assumptions made regarding a mark-recapture estimate of population size. All three of these are important assumptions in a mark-recapture study. If marking alters the animal in any way, it can dramatically change the estimate of the population and shift it to be significantly different from the actual population size.

Which event would lead to primary succession?

A landslide causes the removal of the soil and the organisms that live in the area, leaving rock exposed. A landslide causes the removal of the soil and the organisms that live in the area, leaving rock exposed. Such an event would be considered primary succession, which occurs when a disturbance removes the soil and its organisms, as well as the organisms that live above the removed surface. Therefore, only removing mammals, flooding an area, and a forest fire are not sufficient because these events remove organisms but leave the soil. This is because the soil itself is rich in microorganisms, so the removal of organisms is not considered complete. These are examples of secondary succession.

Which of the following is an example of a parasite manipulating its host?

A nematode causing infected ants to display their reddened posterior area, raising the possibility of bird predation A nematode causing infected ants to display their reddened posterior area, raising the possibility of bird predation is an example of a parasite manipulating its host. Parasites manipulate their host for their own benefit and at the cost of their host. If both species are benefitting from the interaction (as is occurring in the other examples), it is no longer considered parasitism but mutualism.

Which example supports the hypothesis that predators hold populations below carrying capacity?

A wolf control program in Alaska decreased the abundance of wolves from 55% to 80% below precontrol density. During this period, the moose population tripled. A wolf control program in Alaska decreased the abundance of wolves from 55% to 80% below precontrol density. During this period, the moose population tripled. This example supports the hypothesis that predators hold populations below carrying capacity. If prey populations increase significantly with the removal of a primary predator, the system is said to be under top-down control or that predators are a key regulator of population numbers. The other examples exhibit little regulation of prey populations.

Which population would be most likely to experience exponential growth?

A young population with few individuals.

According to the figure, which country is per capita the worst producer of carbon dioxide (CO 2) emission?

According to the figure, Canada has the highest emission per capita. That is, per person in the country Canada releases the highest amount of CO2. China produces significantly less emissions per person, but because there are so many people their total emissions are by far the greatest of any country. The United States has far fewer people than China but is the second worst overall in CO2 emissions because of the relative high level of per capita emissions. India has the lowest per capita emissions of the four countries, but again because it has such a large population it has significantly higher emissions than Canada.

One reason areas near the equator get more rainfall than areas about 30 degrees north or south latitude do is that __________.

Air near the equator rises, cooling as it rises and losing its ability to hold water vapor. One reason areas near the equator get more rainfall than areas about 30 degrees north or south latitude do is that air near the equator rises, cooling as it rises and losing its ability to hold water vapor. The water vapor condenses and falls as rain. Because the equator has near-constant tropical warmth, this air is continually rising and causing frequent rain events. Cooler air is pushed toward the poles and has cooled enough to descend around 30 degrees north and 30 degrees south latitude. These areas are often dry. This is because as the air descends, it warms and increases its water-holding capacity, retaining moisture and creating warm, dry, arid conditions.

All else being equal, which islands are expected to have a higher species richness?

All else being equal, islands at lower latitudes are expected to have more species richness. Several components help determine species richness at a site. Larger islands that are close to mainland source populations will average higher species numbers. Newer islands have had less time for colonists to take hold and are typically less diverse than older islands. Finally, there is a global pattern of higher diversity near the equator. The effect of latitude is far greater than these other factors.

Which of the following leads to growth of a population?

All the fleas living on your dog A population is a group of individuals of the same species living in a defined area at the same time. Thus, all the fleas (group of individuals) living on your dog (defined area) constitute a population. For all of the other answers, members of more than one species are involved. These groups do not represent populations.

Which of the following is an example of ecosystem studies?

An example of ecosystem studies is researching how the energy in sunlight dissipates as it flows through an ecosystem. Ecosystem studies examine how abiotic components such as sunlight are linked by the flow of energy and the cycling of nutrients needed to sustain life.

Which lake zone would be absent in a very shallow lake?

Aphotic zone A lake could be shallow enough that light could penetrate all the way to the bottom, thereby causing it to be lacking an aphotic zone. It will always have a bottom, or a benthic zone. It will also always have a shallow area, or littoral zone. The deeper part of a lake is referred to as the limnetic zone, but this is a relative reference, and even shallower lakes possess them. A pelagic zone is a term used in reference to a marine system.

Bouchard and Brooks studied the effect of insect flight on dispersal and speciation in rain forest insects. They sampled all of the insects in the study area and found that 60 insect species are flightless, and 19 are able to fly. What conclusion can be drawn from this data?

Based on the information given, a reasonable conclusion is that flightless insects have a higher richness in the study area. Species richness is the number of species in an area. Because more flightless species were observed than those able to fly, researchers can conclude a higher richness of flightless insects. Despite having more species, there is no conclusive data that reveals anything about the abundance of flightless insects; there might be many more species, but all are rare. Therefore, flying insects could be more numerous. Further studies would be required to determine why these patterns exist. The results described do not give any indication of tests of fitness and adaptive advantages, so it is impossible to determine which group is better suited to the tropics.

Aphids drinking plant fluids are considered a(n) ____________.

Ectoparasite Aphids have an overall negative interaction with plants by parasitizi ng fluids. Because they are feeding on the plant fluid from the outside of the host, they can be considered an ectoparasite. They are not considered a parasitoid because they are not laying eggs within the plant that then turn into larvae that feed on the plant. They would also not be considered a predator because they are not killing the organism. They share some characteristics as a herbivore in that they both feed on plant nutrients. Generally, though, herbivores are much larger than their plant food and are consuming leaves, stems, fruits, or roots.

Which region on Earth receives the most solar radiation per unit area over a year?

Equator

A butterfly that consumes nectar from a flower would be considered a ____________.

Herbivore

Which of the following statements explains why herbivores eat so little of the food available to them?

Herbivores are kept in check by predation and disease. This explains why herbivores eat so little of the food available to them. Herbivores must balance their requirement for resources with the risk of predation or disease. More time spent eating puts individuals at higher risk of being attacked. Herbivores consume much more food when these threats are removed.

Which is true of human impacts on the global water cycle?

Human alteration of the global water cycle has resulted in the water table dropping on every continent. Asphalt and pavement often divert rainwater that would normally recharge aquifers. Crops typically have simple root systems and contribute to issues of water conservation by requiring continual irrigation from other natural sources. Water used in irrigation is taken up by plants and also has high rates of evaporation; thus, it does not effectively replenish groundwater.

Humans have substantially altered the global nitrogen cycle over the past century. How?

Humans are responsible for almost doubling the amount of nitrogen available by natural means. Primarily through the use of fertilizers, humans are responsible for dramatically increasing the amount of available nitrogen on the planet. Global warming has not directly reduced the conversion of nitrogen (N2) to ammonium (NH4+) and in many places has likely increased this conversion via the increased productivity of decomposers. Although nitrous oxide is a greenhouse gas that is produced from burning fuels, it is not an available form of nitrogen. Previous

White-tailed deer were quite rare across the northeastern United States approximately 100 years ago, but now their populations are generally considered to be too high. What do you predict has caused this?

Hunting females was prevented, and the intrinsic fecundity rate is actually quite high. The leading cause for the dramatic increase in the white-tailed deer population in the northeastern United States is that hunting females was prevented, and the intrinsic fecundity rate is actually quite high. As deer hunting is quite popular, restrictions are placed on females to increase the net reproductive rate of the population. Because many hunters take pride in the antlers of male deer, this was a suitable regulation that was successful in recovering the deer population. Hunters would go into habitat wherever the deer might be, and diseases would emerge again if they were the initial limiting factor of the population.

Experiments performed on the bridled goby in coral reefs and on song sparrows on Mandarte Island support the hypothesis that density-dependent effects can cause logistic population growth. What conclusions can be drawn from logistic growth models?

Individuals survive better and clutch size increases when the population density is low. The conclusion drawn from logistic growth models is that individuals survive better and clutch size increases when the population density is low. When density is high, it is more difficult for individuals to survive because they must compete with these individuals. This means that there also is less energy available to produce larger clutches.

During the Zootoca vivipara study, researchers monitored individuals on a daily basis to document the number of young produced by each female in the wild. What would be the best way to obtain the same type of data but not have to visit the site every day?

Install cameras on site to monitor lizard a The best way to observe the lizards without having to visit the site is to install cameras on site to monitor lizard activity. The use of cameras on site is a handy technique to reduce the need to visit sites in person each day so long as the cameras can adequately detect the species studied. Bringing the population to the laboratory might result in variations caused by the artificial environment. Implanting tracking devices might also dramatically alter an individual's reproduction.

Which statement best describes the evolutionary significance of mutualism?

Interaction increases the survival or population growth rate(s) of both species. Mutualistic interaction increases the survival or population growth rate(s) of both species. Mutualisms are described as the interatction of two species that have positive effects on one another. At some level, this interaction will result in some increase in survival or reproduction. These effects can be varied and might demonstrate better resistance to parasites or more efficient energy usage but does not do all of these in every case. The benefits of a mutualistic relationship may include increased biodiversity, but this type of relationship could also potentially reduce biodiversity or increase competition, depending on the context and what the mutualism involves.

What is the trade-off between life expectancy and fecundity?

Investing more resources in reproduction means there are fewer resources available for survival. An organism has a finite amount of resources. The trade-off between life expectancy and fecundity is that investing more resources in reproduction means there are fewer resources available for survival. Fecundity is the number of offspring a female can have each season. Having more offspring comes at a cost; individuals without offspring, and not those with many offspring, tend to live longer.

New Zealand lies between 36 degrees and 47 degrees south latitude and 165 degrees and 180 degrees east longitude. During which month would the weather be coldest and the days shortest?

June New Zealand would experience the coldest, shortest days during June. Areas south of the equator have winter during the same months that the Northern Hemisphere has its summer. This is because of the tilt of Earth. If the North Pole is pointed toward the Sun, then the South Pole accordingly must be pointed away from the Sun. Therefore, as June is considered summer in the north, it is considered winter in the south. Winter is when the days are both shortest and coldest. The east and west designation of longitude is not important in determining the season.

A(n) __________ summarizes the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime.

Life table A life table summarizes the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime. An age class is a group of individuals of a specific age. A cohort is a group of the same age that can be followed through time. Demography is the study of factors that determine the size and structure of populations through time.

Which zone is found only in freshwater environments?

Littoral zone The littoral zone is the shallow zone of lakes and ponds often filled with leaf litter in forested areas; the littoral zone is found only in freshwater environments.. The marine shallow zones are intertidal zones that describe the influence of the tides on those areas.

Which is an example of Müllerian mimicry?

Many different species of stinging wasps look very similar, with black- and yellow-banded bodies. Many different species of stinging wasps look very similar, with black- and yellow-banded bodies. This is an example of Müllerian mimicry. Müllerian mimicry is often confused with Batesian mimicry. In Müllerian mimicry, species appear similar to one another because both share a common dangerous trait, such as venom or poison (not herbivory). In Batesian mimicry, one of the species does not possess that trait (e.g., harmful sting) but looks like a species that does. imicry can also be confused with cryptic coloration. Cryptic coloration is the "mimicking" of a particular background to provide camouflage. The bee fly exhibits Batesian mimicry, in which the mimic is harmless. The frogfish is exhibiting cryptic coloration. The possums are exhibiting convergent evolution.

Which of the following statements is true of net primary productivity?

Marine productivity is highest along coasts and in areas where water wells up from the ocean floor to the surface. Areas where nutrients well up from the ocean floor provide high levels of productivity in coastal areas. The shallow water along coasts receives more nutrients because rivers carry nutrients from terrestrial ecosystems and deposit them on the coasts, and near-shore ocean currents bring nutrients from the cold, deep water of the oceanic zone up to the surface, a process called upwelling. There is some productivity in the depths of the oceans, although the source of energy might not be sunlight. The highest areas of productivity are the tropics, followed by temperate areas, and then desert and artic regions.

Why can meta populations remain stable over time even if some sub populations go extinct?

Migration from other subpopulations can repopulate habitat fragments left vacant by extinction. Metapopulations remain stable over time even if some subpopulations go extinct because migration from other subpopulations can repopulate habitat fragments left vacant by extinction. Metapopulations are made up of small, isolated populations. Individuals from these distinct populations can reestablish populations in areas where local extinctions might occur. The migration of individuals is important in understanding metapopulation dynamics.

Which of the following descriptions is an inference that can be made from these age pyramid models?

Older men are more common in developed countries An inference that can be made from age pyramid models is that older men are more common in developed countries. Age pyramid models divide the population into distinct age and gender groups that allow one to easily view survival in terms of these two factors. This figure shows that a larger number of older males survive in a developed country such as Sweden when compared with a developing country such as Honduras. A bulge in the pyramid can signify a population boom in the past but is not associated with gender. Predictions about growth rates are difficult to determine with age pyramids.

Which interaction belongs in the +/− category of interactions between species?

Parasitism Parasitism occurs when one species gains and the other is harmed in the interaction; predation and herbivory are other examples of these interactions. Positive interactions among two species are known as mutualisms; most cases of pollination are examples. Commensalism occurs when one species benefits but the other is unaffected.

Which of the following is true about the components of ecosystems?

Primary producers are autotrophs or "self-feeders" within ecosystems. Primary producers generate chemical energy by capturing it from abiotic sources like the Sun (other sources, like sulfur from hydrothermal vents, can be used). Primary consumers feed on primary producers. Secondary consumers feed on primary consumers and, hence, are in the third trophic level. In most ecosystems, primary producers use solar energy to manufacture food via photosynthesis. But in deep-sea hydrothermal vents and iron-rich rocks deep below Earth's surface, primary producers use the chemical energy contained in inorganic compounds such as methane (CH4) or hydrogen sulfide (H2S) to make food. Detritivores are organisms that feed on dead organisms or their waste products.

This feature of aquatic habitats varies from 0.06 parts per thousand up to 35 parts per thousand.

Salinity The proportion of solutes dissolved in water determines its salinity, generally measured as the number of grams of solute per kilogram of water—a unitless number described as parts per thousand. The salinity of fresh water varies from about 0.06 to 0.3 parts per thousand, whereas the salinity of the open ocean is fairly constant at 35 parts per thousand. The other features such as oxygen and nitrogen concentration do not necessarily fall in the stated range. Turbidity is measured by observing the light penetration of a water sample.

When sea otters became extremely rare on the California coast, their usual prey (sea urchins) became overabundant and consumed most of the kelp that was the principal habitat for a diversity of fish species and invertebrates. Which statement best describes this situation?

Sea otters are keystone species. A keystone species is defined as having a much greater impact on the distribution and abundance of the surrounding species than its own abundance and total biomass would suggest. Because sea urchins are highly abundant and make up a large amount of biomass, their impact on the system is not out of proportion. Sea otter predators are far fewer and yet play a key role in maintaining urchin populations. This is a predatory interaction and, therefore, is negative for the urchins and not considered a mutualism.

Which of the following statements about soil organic matter is true?

Soil organic matter is rich in humic acids.

Which species are most likely to be endangered by human activities?

Species with high juvenile mortality, low adult mortality, and low fecundity Most species endangered by human activities have high juvenile mortality, low adult mortality, and low fecundity. Species with low fecundity and low adult mortality are at particular risk of being endangered by human activities. When humans impact a habitat, it often results in large losses to adults. To species with high juvenile mortality, this loss of adults is significant as there are few adults to begin with. In addition, with low fecundity of any remaining adults, populations have a more difficult time rebounding from heavy losses.

An area with moderate annual overall temperature, moderate variation in temperature, and moderate annual variation in rainfall but relatively low overall rainfall would be __________.

Temperature Grassland An area with moderate annual overall temperature, moderate variation in temperature, and moderate annual variation in rainfall but relatively low overall rainfall would be temperate grasslands. Temperate grasslands exist in seasonal areas with little rainfall. Deserts would have extreme temperatures. Temperate forests would have high overall rainfall. Tropical rain forests would average higher in both and possess little variation in temperature.

Which aspects of a region most influence where different types of plants exist?

Temperature and moisture Earth's biomes are determined by the patterns of temperature and moisture. Therefore, the climate determines what type of vegetation will occur in a region. The other factors (sunlight, wind, and soil composition) can greatly impact specific species of plants and animals, yet these are nowhere near as significant as temperature and moisture.

Over the past decade, which of the following has occurred?

Terrestrial net primary productivity (NPP) has decreased in some parts of the world but increased in others. NPP has been affected by global climate change over the past 10 years. This effect has been varied across the globe, resulting in decreases in NPP is some areas (such as the Sahara) and increases in other areas (such as Greenland).

Which of the following is an indicator of net primary productivity (NPP)?

The aboveground plant biomass Net primary productivity (NPP) is the total amount of carbon that is fixed per year minus the amount that is oxidized via respiration. This basically refers to the amount of tissue that a plant produces, the aboveground plant biomass. Sunlight plays an important part in this process, but not all sunlight is captured and converted to plant tissue. Temperature is also important in determining NPP but is not as reliable an indicator. The invasiveness of a species is not typically related to its NPP.

Biologists identify and characterize climate in an area primarily by analyzing _______.

The area's average annual temperature and precipitation and annual variation in temperature and precipitation. Biologists identify and characterize climate in an area primarily by analyzing the area's average annual temperature and precipitation and annual variation in temperature and precipitation. Climate is dictated by both the average and variation of temperature and precipitation in an area. Altitude does impact both of these factors, but not all altitudes correspond similarly. Therefore, directly examining the temperature and precipitation is a more reliable measure. The longitude has no effect on these factors, but the latitude (north to south) does. Species composition is a result of climatic factors and not the cause of them.

If the direction of Earth's rotation reversed, the most predictable effect would be __________.

The direction of ocean currents would be altered. If the direction of Earth's rotation reversed, the most predictable effect would be that ocean currents would alter direction. The spin is also responsible for day and night, but the direction is unimportant, other than what directions the sun would rise and set. Seasonality is caused by the tilt of Earth and the year by the rotation of Earth around the sun.

Ecologist Joseph Connell studied two barnacle species, Chthamalus stellatus and Balanus balanoides, which had a stratified distribution on rocks found on the Scottish coast. Chthamalus tended to cluster higher up on the rocks, whereas Balanus was found lower on the rocks. When Balanus was removed from the habitat serving as the experiment site, Chthamalus spread into the area in the lower intertidal zone, which had previously been covered by Balanus. Which of the following statements is a valid conclusion of this experiment?

The removal of Balanus shows that the realized niche of Chthamalus is smaller than its fundamental niche. The removal of Balanus shows that the realized niche of Chthamalus is smaller than its fundamental niche. The experiment provides evidence that Balanus is limiting the distribution of Chthamalus, yet it is unknown based on the data presented why or if the reverse is true. Balanus may survive only in the lower intertidal zone because it is unable to resist desiccation, but the information presented does not lead to that conclusion. Feeding at different times of day is a form of niche partitioning that allows two species to coexist, but this experiment indicates that the species do not coexist.

In ecosystems, why is the term cycling used to describe material transfer, whereas the term flow is used for energy exchange?

The term cycling is used to describe material transfer, whereas the term flow is used for energy exchange because materials are repeatedly used, but energy flows through and out of ecosystems. Unlike energy that enters an ecosystem and is ultimately dissipated as heat, nutrients such as carbon, nitrogen, and phosphorus move indefinitely through ecosystems in biogeochemical cycles. Material can be moved up and down a trophic chain in a cycling fashion, such that carbon can be obtained from the soil and then contributed directly back to it when a plant dies. Energy, by contrast, flows from the sun to lower trophic levels (producers) up to higher ones (consumers) in a more singular direction.

Why are the spring and fall lake turnovers important for aquatic ecosystems?

The turnovers bring nutrient-rich water from the bottom of the lake up to the top of the lake. The spring and fall lake turnovers are important for aquatic ecosystems because the turnovers bring nutrient-rich water from the bottom of the lake up to the top of the lake. A lake turnover is caused by changing temperatures in the lake and results in a massive upwelling of nutrients to the surface of lakes. The oxygen levels are low at the bottom of the lake. Bottom-dwelling organisms would likely not require vitamin D because they are not normally exposed to light. The melting of the ice is the cause of the turnover, not the effect.

Major human impacts on ecosystems include farming, logging, and burning. These processes all result in accelerated nutrient export by what common mechanism?

Vegetation removal Major human impacts on ecosystems include farming, logging, and burning. These processes all result in accelerated nutrient loss by vegetation removal. Because plants regularly uptake nutrients from the soil, their removal has profound impacts on the nutrient flow within a system. The loss of vegetation results in increased erosion, soil compaction, and loss of habitat as well. Environmental pollution can disrupt the nutrient cycle, but in some cases will contribute to increased nutrients rather than loss because of the effects of fertilizer runoff.

Which of the following statements is an example of a negative feedback loop?

Warmer conditions lead to increased photosynthetic rates and hence an increase in uptake of carbon dioxide (CO2), which could decrease the temperature. This is an example of a negative feedback loop. Negative feedback in climate change occurs when changes caused by global warming result in increased uptake and sequestration of CO2 and other greenhouse gases—meaning that global warming should be reduced. A positive feedback loop occurs when the changes contribute to further increases in global warming, as is seen with warming in the tundra and fires leading to more CO2 emissions which, in turn, lead to more fires.

Which of the following actions changes the abiotic components of an organism's environment?

Water sedimentation

Under what conditions might r, the per capita rate of increase, approach rmax, the intrinsic rate of increase?

When resources are abundant When resources are abundant, r, the per capita rate of increase, might approach rmax, the intrinsic rate of increase. The per capita rate of increase is typically limited primarily by resource availability. Therefore, abundant resources are key to reaching this maximum rate. The other three events would serve to reduce growth rates of a population.

Which of the following statements about competition is true?

When two competitors have slightly different fundamental niches, the poorer competitor can often take refuge in areas that are beyond the better competitor's tolerance. When two competitors have slightly different fundamental niches, the poorer competitor can often take refuge in areas that are beyond the better competitor's tolerance. For competitors to coexist, one competitor must find areas or resources that the other cannot use or tolerate well. If they share the exact same resources and space, the better competitor will eventually exclude the poorer one.

When do lake turnovers occur?

When water at the top of the lake becomes denser than the water below.

n some European countries, the population is declining. In these countries, the net reproductive rate, R0, is __________.

less than 1 In European countries in which the population is declining, the net reproductive rate, R0, is less than 1. Populations will increase when the net reproductive rate is greater than 1 and decrease when it is less than 1. This value can be estimated via the construction of life tables.

Although humans are widely dispersed across the globe, until relatively recently most people rarely ventured more than a short distance from their home region. Because all humans are members of the same species, we form a __________.

metapopulation Humans are members of a single species whose members are distributed in geographically dispersed, patchy regions. It is still possible for some exchange of members to occur, however, so humans can be said to form a "population of populations," or a metapopulation. A cohort is a group of individuals of the same age whose members can be tracked. A community is a group of interacting species, so because humans are only a single species we cannot form a community. Carrying capacity is the number of individuals that can be sustainably supported by an environment.

Which of the following is a constant for a given species?

rmax, the intrinsic rate of increase For a given species, rmax, the intrinsic rate of increase, is constant. The word intrinsic implies that it is a factor integral to that species' life history. rmax is the maximum rate at which a species can reproduce and is dictated by the life history of the species. The carrying capacity depends on the habitat, and the population size fluctuates based on changes in the environment. The per capita rate of increase (r) can change over time and be different among populations based on factors such as weather.