Exam 53 55

Refer to the accompanying figure. At which point on the graph is the population increasing exponentially?

B

Figure 53-6 represents the age structure diagram of:

a highly developed country

Density-independent factors:

are typically abiotic

In the accompanying figure, the gull has the highest concentration of DDT because it is:

at the top of the food chain

Bacterial decomposition of organic nitrogen results in the production of:

atmospheric nitrogen

Organisms that manufactures their own food are known as:

autotrophs

Match the component of the nitrogen cycle with its description. a. assimilation b. denitrificaiton c. nitrification d. nitrogen fixation ___ converts nitrate to gaseous nitrogen

b. denitrificaiton

Less-developed countries are most likely to be characterized by:

high infant mortality rates

Which the size of a population greatly exceeds K, we can expect that the population will:

rapidly decrease

Generally, r-selected organisms exhibit:

short life spans and early maturity

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?

+50

Based on the accompanying figure, which of the following age intervals has the highest death rate?

0-1

Which statement best describes a typical food chain?

An owl has a positive impact on the grass population.

On the accompanying figure, identify the point that indicates the carrying capacity for this population.

D

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

Earth's tilt on its axis

True of False (caps was underlined) In a food chain, primary consumers occupy the FIRST trophic level.

False

True or False (caps was underlined) An example of a density-INDEPENDENT factor is predication.

False

True or False (caps was underlined) Nitrogen fixation is the process by which gaseous nitrogen is converted to NITRATE.

False

The accompanying figure models a(n) _______- shaped growth curve.

S

True or False (The cap was underlined) A killing frost in an example of a density- INDEPENDENT factor.

True

True or False (The cap was underlined) The largest population that can be maintained in an environment for an indefinite period of time is called the CARRYING capacity.

True

True or False (The cap was underlined) In the carbon cycle, one of the ways in which carbon in returned to the atmosphere is by RESPIRATION.

True

True or False (caps was underlined) A decomposer is also called a(n) SAPROTROPH.

True

True or False (caps was underlined) One element that does not cycle into the atmosphere is PHOSPHORUS.

True

True or False (the cap was underlined) Algae and cyanobacteria are examples of PRIMARY PRODUCERS.

True

What is a typical feature of K-selected organisms?

a low reproductive rate

Clumped dispersion is often by:

a patchy distribution of resources

Match the component of the nitrogen cycle with its description. a. assimilation b. denitrificaiton c. nitrification d. nitrogen fixation ___ the process by which animals convert plant nitrogen compounds into animals nitrogen compounds

a. assimilation

At zero population growth:

b=d

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

bacteria

The graph in the accompanying figure would best be described as:

being a J-shaped curve characteristic of exponential growth

Match the component of the nitrogen cycle with its description. a. assimilation b. denitrificaiton c. nitrification d. nitrogen fixation ___ carried out by nitrifying bacteria

c. nitrification

To date, humans have interfered with all of the biogeochemical cycles on Earth, but this interference has been of the greatest magnitude, in terms of human-induced changes in climate, in the:

carbon cycle

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.

carbon dioxide, oxygen and nitrogen

Match the component of the nitrogen cycle with its description. a. assimilation b. denitrificaiton c. nitrification d. nitrogen fixation ___ converts N2 to NH3

d. nitrogen fixation

Based on the accompanying figure, the decline in the moose population in 1996 was mostly likely due to a(n):

decline in the food supple

The world human population has increased dramatically during the past few centuries due to:

decreased death rates

Match the population-influencing factor or definition with its type. a. density dependent b. density independent ___ disease

density dependent

Match the population-influencing factor or definition with its type. a. density dependent b. density independent ___ can cause an decrease in birth rat e

density dependent

Match the population-influencing factor or definition with its type. a. density dependent b. density independent __generally cause an increase in death rate

density independent

Match the population-influencing factor or definition with its type. a. density dependent b. density independent ___ severe blizzard

density independent

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

gross primary productivity

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

natality

Which process is not involved in the hydrologic cycle?

nitrification

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

of one species in a given area at a given time

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

organisms rarely eat just one kind of food

Four of the five answers listed below reflect how humans have disturbed the balance of the global nitrogen cycle. Which is the exception?

overuse of refrigerants

Which process does not return carbon to the atmosphere?

photosynthesis

Fixation of carbon is accomplished by:

photosynthetic organisms

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

population - community - ecosystem - biospher

Natural selection acts most directly on:

populations

Communities are composed of all of the:

populations of all different species that live together within an area

Which pair best represents photosynthetic organisms?

primary producer and autotroph

The atmosphere performs several essential ecological functions. One of these is to:

protect Earth form most ultraviolet radiation

Which trophic level would contain the lowest quantity of energy (kcal per m^2)?

tertiary comsumers

Net primary productivity represents:

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

Refer to the accompanying figure. How would the survivorship curve for elephants be represented?

the curve C

When r=-0.00057, the population size:

will decrease