midterm 3 bio

The main steps of the nitrogen cycle are:

nitrogen fixation, nitrification, assimilation, ammonification, and dinitrification.

Bacteria are most essential in the cycling of

nitrogen.

Nitrogen is a critical requirement for living organisms because it is a component of:

nucleic acids and proteins.

The ____ contains the greatest volume of ocean water.

oceanic province

A food web is a more realistic depiction than a food chain because:

organisms rarely eat just one kind of food.

Within a community, a dominant species may appropriate a disproportionate share of available resources, thus ____ other species.

outcompeting

Which term can be applied to both monotremes and sharks?

oviparous

Most reptiles are ____ and their fertilization is ____.

oviparous; internal

An example of a density-dependent factor that influences the size of a population is:

parasites

In a parasitic relationship where the host contracts a disease and sometimes dies, the parasite is called a(n):

pathogen.

Which nutrient cycle does not have a gaseous phase?

phosphorus cycle

Fixation of carbon is accomplished by:

photosynthetic organisms.

Which of the following series correctly represents the hierarchical organization within ecology?

population → community → ecosystem → biosphere

Which pair best represents photosynthetic organisms?

primary producer and autotroph

Species richness is ____ when any one species enjoys a position of dominance.

reduced

Birds are most closely related to:

reptiles

Surplus individuals in the ____ disperse and find another habitat in which to settle and reproduce.

source habitats

Which of the following organisms would have the highest intrinsic rate of increase?

Bacteria

A frog that lacks chemical defenses, yet resembles a poison arrow frog, would exhibit:

Batesian mimicry.

Which statement about biomass is FALSE?

Biomass reduction from one trophic level to the next is approximately 50%.

Which country would be expected to have the greatest species richness per unit area?

Brazil

The primary reason that Earth experiences seasons is because of the:

Earth's tilt on its axis.

El Niño-Southern Oscillation has resulted in:

global weather changes.

The organisms occupying the base of a pyramid of energy are autotrophs.

True

Clumped dispersion is often influenced by:

a patchy distribution of resources

The ____ niche is the broadest role that an organism can potentially have in a community.

fundamental

Organisms that eat plants exclusively are known as______.

herbivores

In a population characterized by type III survivorship, the probability of survival ____ with age.

increases

In Experimental Condition 2 of the accompanying figure, the distribution of Chthamalus suggests that:

interspecific competition kept Chthamalus from extending lower into the intertidal area.

Competitive exclusion is a result of:

interspecific competition.

One reason that the realized niche and fundamental niche are not typically the same is:

limiting resources.

The marine euphotic zone is comparable to the ____ zone of lakes.

limnetic

The most productive region of a lake is the ____ zone.

littoral

An example of both chemical protection and coevolution can be seen in:

milkweeds and monarch caterpillars.

The best definition of population density is the number of individuals:

of one species in a given area at a given time.

About __________ of the total energy the sun releases strikes the atmosphere.

one-billionth

Iteroparity is common in which of the following organisms?

perennial herbaceous plants

Solar radiation

powers the hydrologic and other biogeochemical cycles.

In tropical and temperate regions, ____ becomes more significant than temperature.

precipitation

Organisms such as oysters or fish that produce millions of eggs per year may be characterized as:

r-selected and having a type III survivorship curve.

In which group did the amniotic egg first evolve?

reptiles

Populations that experience significant contest competition:

show great changes in population size over time.

The wide adaptive radiation of mammals occurred during the early ____ era.

Cenozoic

A linear depiction of energy flow in an ecosystem is a(n):

Food Chain

____ is the least frequent of the dispersal patterns seen in nature.

Random dispersion

Resource partitioning may include which of the following?

Relocating nesting sites

In Experimental Condition 1 of the accompanying figure, the distribution of Balanus suggests that:

an unfavorable environmental factor kept Balanus from extending higher into the intertidal area.

During ____ between predator and prey species, the predatory species becomes more efficient at catching prey, while the prey species becomes better at escaping predators.

coevolution

What would be the growth rate (r) of an island population of 1000 that has 30 births per 100 population, 20 death per 100 population, 5 immigrants per 100 population, and 10 emigrants per 100 population?

+5%

What would be the growth rate (r) of an island population of 6000 birds that has 50 births per 600 birds, 30 death per 600 birds, 5 immigrants per 600 birds, and 20 emigrants per 600 birds? [Provide your answer with at least three significant digits]

0.0083 (with margin: 0.0005)

Arrange the following from the ecosystem with the smallest average NPP to the ecosystems with the largest NPP. 1) lake 2) savannah 3) estuary 4) tropical rain forest 5) open ocean

5, 1, 2, 3, 4

About ____ species of birds have been described.

9,000

Which scenario best describes facilitation?

A species interaction that modifies and enhances the local environment for other species

What environment is characterized by high nutrient inputs and by relatively great fluctuations in salinity and temperature?

An estuary

Climates characteristic of the Mediterranean region are also common in:

California

An herbivore occupies the third trophic level.

False

Competition between species 1 and species 2 is beneficial for species 1 and harmful for species 2.

False

K strategists typically produce large numbers of offspring.

False

Source habitats are areas where reproductive success is less than local mortality.

False

Species that exhibit repeated reproductive cycles are said to be semelparous.

False

The most abundant gas in the atmosphere is oxygen.

False

The potential ecological niche of a species is its realized niche.

False

In an ecosystem, which measure of energy is the largest in amount or rate?

Gross primary productivity

The event in human history that changed the natural balance of the carbon cycle was the:

Industrial Revolution

The Southern Hemisphere has no equivalent of the boreal forest of the north. Why?

It has no land in the corresponding latitudes.

Tawny owls (Strix aluco) pair-bond for life, with both members of a pair living and hunting in adjacent, well-defined territories. Their reproduction is regulated in accordance with the resources, especially the food supply, present in their territories. Tawny owls can best described as:

K strategists.

What term refers to the average rate at which organisms produce offspring?

Natality

Which of the following would increase population size?

Natality

The enzyme nitrogenase is important in which part of the nitrogen cycle?

Nitrogen fixation

Which are the three main roles played by organisms in community life?

Producer, consumer, decomposer

An example of mutualism is:

Rhizobium and legumes.

____ begins in an area where there was a preexisting community and well-formed soil.

Secondary succession

____ generally have greater population densities than less suitable sites.

Source populations

Order ____ includes the snakes.

Squamata

Which trophic level would contain the lowest quantity of energy (kcal per m2)?

Tertiary consumers

The idea that older, more stable habitats have greater species richness than habitats subjected to frequent, widespread disturbances is known as:

The Time Hypothesis

Fossil fuels, such as coal and oil, are derived from which biogeochemical cycle?

The carbon cycle

Which statement about decomposers is FALSE?

They include bacteria but not fungi.

How are bacteria important to the genus Rhizobium?

They provide fixed nitrogen to legumes.

A decomposer is also called a saprotroph.

True

Convergent evolution resulted in placental and marsupial mammals with similar structural features.

True

In a food chain, producers occupy the first trophic level.

True

What ecosystem has the highest rate of primary productivity?

algal beds and reefs

A community consists of ____ species in a given area.

all

Nitrogen-fixing bacteria convert gaseous nitrogen into

ammonia.

The tetrapods include:

amphibians, reptiles, birds, and mammals.

Density-independent factors:

are typically abiotic.

Keystone species:

are typically not the most abundant species in the community.

Which step of the nitrogen cycle is not performed by most bacteria?

assimilation

Plant roots absorb nitrate or ammonia and incorporate these compounds into plant proteins via the process of

assimilation.

The growth rate of a population is expressed as:

b - d

Which set of values would result in a population with a growth rate of zero?

b = 1000, d = 500, i = 500, e = 1000

At zero population growth:

b = d.

The community found on a rotting log would include:

bacteria

Which of the below are living descendants of the dinosaurs?

birds

A primary source of carbon for photosynthetic organisms is

carbon dioxide in the atmosphere and water.

The major components of Earth's atmosphere, from the lowest concentration to the greatest concentration, are

carbon dioxide, oxygen, and nitrogen.

Traditionally, most ecologists have assumed that community stability is a consequence of:

community complexity.

The realized niche for the green anole was determined by:

competition

​The equation that would best describe the curve in the accompanying figure is:

dN/dt = rN.

When the size of a population begins to approach K, we can expect that the growth rate will:

decline.

Which factors are an example of a negative feedback system?

density dependent

Community ____ is the description and analysis of patterns and processes within a community.

ecology

A(n) ____ is the transition zone where two ecosystems meet and intergrade.

ecotone

Characteristics of headwaters include:

fast flow, high oxygen, and streamlined animal bodies.

Within the chordate classes, the unique characteristic of the class Aves is:

feathers

The logistic equation:

takes into account the carrying capacity of the environment.

Currently, much commercial lumber and wood products come from which biome?

temperate rain forest

Near the poles, what is generally the overriding climate factor?

temperature

What two abiotic factors are considered to most affect organisms?

temperature and water

Net primary productivity represents:

the amount of biomass in excess of that needed to support plant cell respiration.

During the cycling of phosphorus, phosphorus does not enter ____ in appreciable amounts.

the atmosphere

Habitat is best described as:

the local environment in which a species lives.

Mammals descended from a group of reptiles known as:

therapids

Much precipitation in the tropical rain forest is derived from:

transpiration