Ecological Pyramids & Population Growth

Question 1

The ______% rule shows how energy flows through a food chain. The bottom of the pyramid has the _______ energy.

Answer 1

10% - most

Question 2

When analyzing an energy pyramid, how much energy is LOST as you move up to the next trophic level?

Answer 2

90%

Question 3

True or False : There are usually more producers in an ecosystem than consumers.

Answer 3

True

Question 4

The measure of the total dry mass of organisms in a given area is _____

Answer 4

biomass

Question 5

Which level of the ecological pyramid usually has the MOST biomass?

Answer 5

Producers

Question 6

Which trophic level would contain the least amount of organisms?

Answer 6

Tertiary consumers

Question 7

Which organism in the food web would contain the highest concentration of chemical pollutants?

Answer 7

tertiary consumers

Question 8

The accumulation of pollutants at higher trophic levels is called…

Answer 8

Biomagnification

Question 9

How can a population size increase?

Answer 9

immigration

Question 10

How can a population size decrease?

Answer 10

emigration

Question 11

Something that would keep a population from growing is called a(n) ___.

Answer 11

limiting factor

Question 12

A wildfire sweeps through a dense forest, burning down everything in its path. A wildfire is a ___.

Answer 12

density-independent limiting factor

Question 13

Mountain chickadees (Parus gambeli) compete for a special kind of nest site—tree holes. These little cavities are excavated and then abandoned by woodpeckers. Scientists added new nest sites in one expanse of forest and saw the chickadee nesting population increase significantly. Based on this information, tree holes are a ___.

Answer 13

density-dependent limiting factor

Question 14

Which type of population growth pattern is due to unlimited resources?

Answer 14

exponential growth

Question 15

What type of population growth pattern shows growth leveling off at the carrying capacity?

Answer 15

logistic growth

Question 16

What causes population growth to slow down during logistic growth?

Answer 16

limited resources

Question 17

The maximum population an environment can sustain is affected by environmental factors that cause the population to level out or become stable. What term is used to describe this threshold?

Answer 17

carrying capacity

Question 18

What can you infer from the drop in the wolf population and the increase in the moose population from 1982-1995?

Answer 18

a deadly virus spread throughout the wolf population