Bio final

If 400 robins are found in a ten-hectare plot, the density of robins in that plot is

40 robins

If a certain age interval in a population contains 10 individuals and has a mortality rate of 1.00, how many individuals are in the next-older age interval?

0

The accumulation of _______ allowed organisms to grow larger.

02 in the atmosphere

Most of Earth's great deserts are located around which latitude?

30 degrees

Eighty-one pocket gophers were present in Maddox Field at the start of 2015. During that year, 24 individuals were born and 19 died. Twelve individuals immigrated, and 10 emigrated. How many pocket gophers were present in Maddox Field at the start of 2016

88

Which is an example of a mutualistic interaction?

A bacterium lives in a plant's roots and fixes nitrogen for the plant, which in turn provides nutrients to the bacterium.

What is the major distinction, if any, between a food web and an interaction web?

A food web shows only trophic interactions; an interaction web shows both trophic and nontrophic interactions.

A species consists of

A group of individuals of the same type share a common geonome

Which is not a characteristic of most living organisms?

Ability to change traits according to need

The thorns on cacti are modified leaves and represent an example of a(n) _______

Adaption

Scientists reported that the reintroduction of wolves into Yellowstone National Park initiated a trophic cascade. Which factual statement best supports this conclusion?

After wolves were reintroduced, the numbers of aspen trees increased.

Which phrase best describes an ecological community, based on the theoretical definition?

All living organisms in a local grassland

Which of the following statements about mutations is incorrect?

All mutations are harmful

While pursuing its prey, a bear destroys a shrub. The relationship between the bear and the shrub would be described as

Amenalism

Which situation is an example of density-independent population regulation?

An early cold spell kills 80 percent of the sparrows in a particular area.

Which statement best describes the difference in the day length at the equator and at the poles as a result of the tilt of Earth's axis?

At the equator, day length is relatively unchanged year-round; at the poles, it varies considerably with seasons.

Although most herbivory harms the plant, some herbivorous interactions do not. Which is not a harmful interaction?

Bears eat blueberries, then excrete blueberry seeds throughout the forest, and the seeds germinate.

Which statement is true

Biologists have discovered only a small percentage of the species that inhabit Earth.

A population is at its carrying capacity (K) when the

Birth rate = death rate

When Mount St. Helens erupted, three relatively distinct zones of destruction resulted: the Pumice Plain, which was essentially sterilized and had no remaining life; the Blowdown Zone on the mountain slopes, where downed trees and vegetation were covered with mud and ash; and farther down, forests that remained standing but were also covered with mud and ash. Based on these levels of destruction, what would the likely rate of recovery be for these zones?

Blowdown zone that recovers faster

a biogeochemical cycle, large amounts of an element can be stored for millions of years and remain relatively untouched. Which is the best example of such a pool?

Carbon in rocks and fossil fuels

The basic structural and physiological unit of most living organisms is the

Cell

Which represents the correct order of the levels of complexity at which life is studied, from most inclusive to least inclusive?

Cell, tissue, organ, organism, population, community

bacterial species lives deep in the ocean, where chemicals including hydrogen sulfide and methane seep out of superheated magma. The bacteria obtain their energy by breaking down these chemicals and building organic chemicals from them. They are carrying out which biological process?

Chemeosynthesis

The diversity of secondary compounds (including drugs) found in plants is primarily due to

Coevolution with herbivores

Two communities are analyzed using the Shannon index of species diversity. Community A has an H value of 1.5. Community B has an H value of 3.0. What is the strongest conclusion that can be drawn about the species diversity of these two communities?

Community A has a lower species diversity than community B.

The sea otter acts as a keystone species in the kelp (giant seaweed) forests of the ocean in the Pacific Northwest. Sea otters feed on sea urchins, which in turn feed on kelp. Crabs, snails, and geese also depend on kelp for food, and many types of fish use the kelp to hide from predators. Sea otter populations are declining in some areas because of increased predation by orca whales. What effect will the decline in sea otters likely have on the kelp community?

Community diversity will decrease as sea urchins overpopulate and overexploit kelp.

Two species of beetles are herbivores on the same host plant, and the presence of either species reduces the population growth of the other. The relationship between the beetles is therefore best described as

Competition

Which description does not fit the definition of an ecosystem study?

Competitive and cooperative interactions among forest-floor beetle species

Two species of yeast can persist indefinitely on agar in the lab, but when they are grown together under similar conditions, only a single species remains after a few days. This interaction is an illustration of

Competitive exclusion

The quadrat method of estimating population size would likely be most appropriate for a population of

Dandelions in a lawn

animal dies near the forest edge. Almost immediately, its dead flesh is attacked and fed upon by bacteria, worms, insect larvae, and scavengers such as coyotes, crows, and vultures. The dead animal is undergoing the process of

Decomposition

Of the following types of ecosystems, which one does not receive its energy from the sun?

Deep-sea hydrothermal vents

A starting population has 150 animals. During the year, 50 animals are born and 30 die. Ten animals immigrate into the population, and 5 emigrate. Which represents the change in population size at the end of the year?

Delta N25

The South American tree sloth feeds on leaves and buds, which are digested by bacteria that inhabit the sloth's stomach. It is difficult for predators to see the sloth in a tree, because it is tinted green from the cyanobacteria that live in its fur. A variety of nonbiting insects also live in the fur but appear not to affect the sloth. This suggests that the sloth has mutualistic interactions with which two sets of organisms?

Digestive bacteria and cyanobacteria

Beavers modify their habitat by building dams, which create wetlands, meadows, and ponds for themselves and other species. Humans also alter habitats, clearing forests and grasslands for agriculture and urban development. Beavers and humans can be considered both

Ecosystem engineers and keystone species

Which type of organisms would be most likely to evolve adaptations that would enable them to grasp onto and maintain a tight grip on their hosts?

Ectoparasites

Which city in the Northern Hemisphere has the least amount of daylight on the shortest day of the year?

Ellesmere Island, Canada, latitude 80°N

A large pond receives sewage runoff from a cattle feedlot and fertilizer runoff from surrounding fields. The runoff contains large quantities of nitrogen and phosphorus. The pond undergoes an algal bloom. The algae die off and are decomposed by bacteria, which depletes the pond's oxygen content. Fish and invertebrates begin to die. What process is the pond undergoing, and changes in what limiting factor or factors initiated the process?

Eutrophication; nitrogen, phosphorus, or both

Change in the genetic makeup of populations over time is known as

Evolution

Which usually results from a scientific investigation?

Formulation of new questions that result in additional experimentation

The branches and canopy of fig trees in tropical rainforests provide habitat for several thousand animal species, including insects, reptiles, birds, and rodents. Their fruit serves as a food source for many species during times of the year when other fruit is scarce. These fruit-eating species in turn provide prey for many different predator species. The benefits provided by fig trees suggest that, in the rainforest, they serve as

Foundation species

rapid decline of amphibian populations has been observed worldwide. Which could not be one of the proposed hypotheses related to this decline?

Frogs die naturally

When ecologists speak of clear-cutting in the Amazon Basin as the "largest experiment on Earth," they are referring to significant and irreversible effects. They are primarily concerned about the ultimate effect

Global biodiversity

If r = 1.0 for a given population, then the population is

Growing rapidly

Research ecologists often specialize in one level of ecology. Which question would most likely be studied by a Yellowstone National Park ecologist specializing in biogeochemical cycles in ecosystems?

How does nitrogen move among the organisms, soil, water, air, and rocks of the park?

A population following a logistic growth pattern

Is not subject to density independent

Which of the following is not true of life?

Life has multiple origins

All of these factors would contribute to making microparasites efficient pathogens except

Likelihood of killing its host

The intermediate disturbance hypothesis states that a community experiencing an intermediate level of disturbance will have higher species diversity than it would with low or high disturbance. What is a major justification for this hypothesis?

Low disturbance would lead to competitive exclusion, high disturbance to more extinctions.

A biologist listens to frogs singing at a local pond and hypothesizes that the sounds are mating calls. What would be the next step in the hypothesis-and-prediction method?

Making a prediction

A group of scientists is studying a population, or pod, of dolphins. They gather information about individual dolphins to determine population characteristics, migration patterns, and other factors. They identify each dolphin by photographing its dorsal fins, providing a photo-ID similar to a fingerprint. Scientists in this study are using which method of studying populations?

Mark recapture method

The Rocky Mountain Parnassian butterfly lives on separate meadows in Alberta, Canada. Individuals live in a single meadow but can fly among meadows. This arrangement would best be classified as a

Metapopulation

The mark-recapture method of estimating population size is most appropriate for use in populations that are

Mobile species

Two equations are often used to describe population growth

Nt is the total population at time t; ΔN is the change in population over a time period.

Although lichens look like single organisms, they are actually an association between a fungus and a photosynthetic partner, usually an alga. The lichen association is considered mutualistic, but the relationship also shows some features of parasitism. Which fact about lichens suggests parasitism rather than mutualism?

Nutrients always flow from algae to fungi but do not always flow from fungi to algae.

Which of these organisms is a primary producer?

Oak tree

Robins eat earthworms, but they also eat a variety of insects and berries. In a food web, the robin would be considered a(n)

Omnivore

Which topic of study would be more appropriate for an environmentalist than for an ecologist?

Park management guidelines that balance species diversity and tourism

Which factors are taken into consideration in the biological classification of organisms?

Physical characteristics, fossil records, and molecular characteristics

Biogeographers classify biomes in terms of their basic climatic conditions, especially temperature and precipitation. Ecologists often classify them in terms of their major plant life. Why do plants represent a good method of biome classification?

Plant types adapt to climatic conditions and reflect the climate of the biome.

Which situation can be considered an example of an abiotic factor acting as an agent of natural selection?

Polar bears with genes for thicker coats were more able to survive intensely cold temperatures, and more of their offspring survived.

Thousands of grasshoppers of the same species live on a single plot of land. They feed on plants in the fields and gardens and reproduce within their own group. This group of grasshoppers represents a

Population

An ecologist is studying a rocky intertidal zone. She maps the area and takes samples to calculate the species diversity. She determines the tidal variations and figures out how long each dominant organism is covered by tides and then analyzes the population density of each dominant species over a year. This ecologist is working at what level(s) of organization?

Population community and ecosystem levels

Rising global temperatures increase the rate of evaporation. The warmer air also holds more moisture. These changing factors are most likely to directly affect which process in the hydrologic cycle?

Precipitation

An r-strategist species typically does not

Provide parental care

Eastern tent caterpillars are social nesters that spin weblike nests, or tents, to which they keep adding layers as they molt and grow. The caterpillars leave the tent several times each day to feed on the leaves of their host tree. Many potential predators will attack one tent caterpillar and then refrain from attacking or eating others. Two possible deterrents to predation are the stiff hairs present on cate

Raise some caterpillars on nontoxic leaves, and offer both toxic and nontoxic caterpillars and pupae to predators.

In the spring, each male redwing blackbird establishes a breeding territory and prevents other males in its population from entering. The distribution pattern of these male redwing blackbirds

Regular

Two similar species of lemurs exist in Madagascar. One species eats leaves from the understory of trees, and the other eats leaves from the tops of those trees. This phenomenon would be described as

Resource partitioning

When applying biology to public policy,

Several countries must be added

Unlike most marine fishes, sharks are K-strategists exhibiting slow growth, delayed maturation, long gestation periods, and production of few young. Sharks have been highly successful for 400 million years, but many are now endangered due to exploitation by human fisheries. In what way is the shark's K-strategy now a detriment, rather than a benefit, to its survival?

Sharks evolved to be top predators, but humans have taken over this role, and sharks cannot reproduce rapidly enough to maintain their populations.

Alpha, beta, and gamma diversity can be used to describe species diversity and composition in terms of their

Spatial scales

Wetland A has four species of frogs, present in the following numbers of individuals: 10, 10, 10, and 2. Wetland B has five species of frogs, present in the following numbers: 10, 10, 10, 10, and 10. What can be said about frog species richness and species evenness in the two wetlands?

Species richness and species evenness are both higher in wetland B.

Which is not one of the major steps in the approach that uses a hypothesis and then a prediction?

Stating an opinion

A Walter climate diagram illustrates the major characteristics of a biome by providing information on the biome's

Temperature and participation

Which statement represents a scientific point of view?

Testing the effect of antibiotics on E. coli can help prevent deaths from food poisoning.

Measurements show that, on average, Northern Hemisphere temperatures are approximately 2°C warmer than Southern Hemisphere temperatures, and they are also more variable. What factor do scientists think might be responsible for these differences?

The Southern Hemisphere has more ocean, which absorbs more heat without raising the temperature.

If secondary consumers are the highest trophic level in a specific community, how many trophic levels are in this community (not counting decomposers or omnivores)?

Three

Lawn A was planted with a single species of grass, which covers 90 percent of the lawn. The other plant species there include five species of weeds, each covering 2 percent of the lawn. Lawn B has the same six species, but with percentages of 75 percent grass and 5 percent for each of the five weeds. How do species richness and species evenness of the two lawns compare?

The lawns have equal species richness, but lawn B has greater species evenness.

The sun's rays are most concentrated at the equator and least concentrated at the poles. What is the main reason for this difference in solar intensity?

The sun strikes Earth directly near the equator and at an angle near the poles.

Which statement best describes the distinction between weather and climate?

The time scale for weather is shorter than that for climate.

When white pine seeds are blown by wind into an open field, young pine trees grow wherever the seeds land. As the pine trees get larger, they begin crowding each other and competing for space and light. Many pine trees die, and those that live are each located at a distance from their nearest neighbors. Which statement is the best description of the dispersion pattern of a white pine population over time?

The trees will be randomly spaced when young and regularly spaced when older.

Which of the following statements about viruses is true?

They depend on cellular organisms to reproduce.

Most mammals have relatively few offspring but sometimes spend years caring for each one. Which trade-off in terms of energy investment are these mammals making?

They invest in parental care as opposed to high fecundity.

If the tilt of Earth's axis were 33.5° instead of 23.5°, how might seasons be different than they are now?

They would be more pronounced in both hemispheres.

Which type of biome has the longest growing season?

Tropical rainforest

Which of these land ecosystems would be expected to have the highest total net primary productivity?

Tropical rainforests

Primary succession is most likely to occur after a(n)

Volcano erupts

Which pattern of survivorship is most likely for an organism such as the sea urchin, which produces large numbers of very small offspring and provides no parental care?

Young individuals have a high probability of dying, but older individuals have a relatively low probability of dying.

Beginning about 500 million years ago, plants began to colonize land. One factor that made this colonization possible was the presence of an atmosphere with high concentrations of carbon dioxide, which was necessary for photosynthesis. This suggests that before colonization, the green aquatic algae that eventually evolved into plants were prevented from forming land communities by

abiotic factors such as environmental gases.

Populations of organisms have been able to inhabit a wide variety of environments on Earth because they

adapt through evolution

The advantage of controlled scientific experiments is that

all variables except one are held constant.

A phylogenetic tree

diagram showing evolutionary relationships of organisms with a common ancestor; resembles a tree

Which is not a step in the scientific method?

discarding data inconsistent with the hypothesis

The patterns and processes of changes in populations are called population

dynamics

upwelling zone off the coast of Peru, in South America, has a very high net productivity. The factor that probably contributes most to the region's high NPP is its

increased nutrients from deep water.

In the northern Pacific Ocean, sea otters feed on sea urchins and sea stars. Sea urchins feed on kelp, and sea stars feed on mussels. Beginning in the 1700s, sea otters were hunted for their fur and driven nearly to extinction in some areas, resulting in trophic cascades in their communities. When the fur trade ended, sea otter numbers increased and their communities began to recover. One would expect this recovery to lead to increased numbers of _______ and decreased numbers of _______.

kelp and mussels; sea urchins and sea stars

Plants and mycorrhizae (fungi that grow in association with plant roots) are usually mutualistic. The fungus absorbs water and minerals, such as phosphorus, from the soil, which the plant uses. The plant provides the fungus with carbohydrates. In soils where phosphorus is low, nutrient transfer from fungus to plant may increase plant fitness. But in very fertile soils, the net benefit of the interaction may become negative, with the

moves along a relationship continuum in response to environmental changes.

Scientific explanations for a natural phenomenon

must be based on reproducible and quantifiable observations

The ultimate source of new genetic variation is

mutation in the geonome

The trapping of heat energy from the sun by gases in Earth's atmosphere is important primarily because it results in Earth's ability to

remain warm enough to support life.

Two species of lionfish have recently invaded the Caribbean, the Gulf of Mexico, and the Western Atlantic region. Comparing these predatory fishes with their native competitors, the activity of the lionfish could best be classified as

strong predators with asymmetrical effects on competitors.

A genome is

sum of all genetic information in a cell

The main purpose of any single experiment is to

test a prediction that is based on a hypothesis

Cells are characterized by

the enclosure of biological molecules by a membrane

Natural selection functions

through differential probabilities of survival and reproductive success

A group of cells that work together to carry out a similar function is known as a(n)

tissue

All of these would be considered strictly ecological studies except

updating endangered species legislation pertaining to fish.

Kudzu originated in Asia and was introduced to the southern United States for uses including cattle fodder and erosion control. Kudzu grows extremely rapidly, obtains resources very quickly, and absorbs nitrogen from the air. Its rapid growth smothers plants, including whole trees, and covers buildings and other structures. These characteristics suggest that kudzu would have what effect on community structure?

would decrease community stability by decreasing or eliminating native species.