Question 1

Choose the letter of the best match from the following:
-Organisms are interrelated;energy transfers through the various trophic levels;there are a low number of herbivores,which are supported by much larger numbers of photosynthesizers.

Accepted Answer

A) ecological pyramid of energy 
B) ecosystem 
C) species diversity cline 
D) food web/food chain 
E) biogeochemical cycles

Question 2

A Viceroy caterpillar feeds on a leaf.If a day's feeding gains the caterpillar a total of 1000 calories and 50% is lost in its feces and 33% of the energy is used through cellular respiration,how many calories of the original intake are available for caterpillar biomass?

Accepted Answer

A) 830 calories 
B) 670 calories 
C) 500 calories 
D) 330 calories 
E) 170 calories

Question 3

What feature do the carbon and phosphorus cycles have in common?

Accepted Answer

A) involvement in acid rain 
B) large mineral deposits 
C) involvement in eutrophication 
D) large atmospheric component 
E) often a limiting nutrient

Question 4

Photosynthesis fixes about

Accepted Answer

A) 0.1% of the CO2 present in the atmosphere. 
B) 1% of the CO2 present in the atmosphere. 
C) 10% of the CO2 present in the atmosphere. 
D) 20% of the CO2 present in the atmosphere. 
E) almost 100% of the CO2 present in the atmospherE.

Question 5

All of the following undergo biogeochemical cycles except

Accepted Answer

A) carbon. 
B) energy. 
C) nitrogen. 
D) sulfur. 
E) water.

Question 6

Which of the following terms could be used by you as you explain to your teacher your understanding of the total amount of organic matter produced in a community in a given time that is available for heterotroph consumption?

Accepted Answer

A) primary productivity 
B) secondary productivity 
C) primary production 
D) net primary production 
E) net secondary production

Question 7

Which one of the following ecosystems is most likely to show an inverted biomass pyramid but a normal energy pyramid?

Accepted Answer

A) grassland 
B) open ocean 
C) intertidal 
D) tropical forest 
E) desert

Question 8

All of the following factors except one affect species richness.Select the exception.

Accepted Answer

A) loss of keystone species 
B) moderate physical disturbance 
C) primary productivity 
D) habitat heterogeneity 
E) species diversity cline

Question 9

Which one of the links in the food chain shown below does the garden spider represent?
Grass-cricket-garden spider-blue jay-red-tailed hawk

Accepted Answer

A) producer 
B) primary producer 
C) primary consumer 
D) secondary consumer 
E) tertiary consumer

Question 10

In a pond ecosystem,a crayfish feeds on three species of algae.It in turn is preyed on by one species of fish and a heron.The heron also preys upon the fish.What is the minimum number of food chains in this food web?

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 5 
E) 6

Question 11

With almost no exceptions,the nitrogen fixers are

Accepted Answer

A) beans. 
B) green plants. 
C) insects. 
D) mammals. 
E) prokaryotes.

Question 12

Factors that could determine productivity of an aquatic community include all of the following except

Accepted Answer

A) nitrogen-fixing bacteriA. 
B) seasonality. 
C) the number of autotrophs. 
D) a limiting nutrient. 
E) rainfall.

Question 13

Heterotrophs must obtain organic molecules that have been synthesized by _____________.

Accepted Answer

A) biogeochemical cycles 
B) bacteria 
C) decomposers 
D) autotrophs

Question 14

Which one of the following explanations for why the tropics have greater species diversity than the temperate zone is least convincing?

Accepted Answer

A) Seasonality variability is less in the tropics. 
B) Niches are narrower in the tropics. 
C) Fewer predators in the tropics allow more prey species to flourish. 
D) Greater spatial heterogeneity in the tropics creates more niches. 
E) The tropics have greater plant production,which supports greater overall species richness.

Question 15

The balance between photosynthesis and ___________ is altered by the combustion of fossil fuels.

Accepted Answer

A) respiration 
B) sunlight 
C) growth 
D) decomposition

Question 16

__________ becomes available to organisms almost entirely through the metabolic activities of a few genera of bacteria.

Accepted Answer

A) Phosphorus 
B) Sulfur 
C) Nitrogen 
D) Iron

Question 17

Choose the letter of the best match from the following:
-All of the organisms that live in a place,together with the physical characteristics of the place;they interact with each other in a dynamic fashion.

Accepted Answer

A) ecological pyramid of energy 
B) ecosystem 
C) species diversity cline 
D) food web/food chain 
E) biogeochemical cycles

Question 18

What feature do the carbon and nitrogen cycles have in common?

Accepted Answer

A) a large atmospheric component 
B) involvement in global climate change 
C) often a limiting nutrient 
D) mostly local cycling 
E) many microbes involved in cycling

Question 19

In a food chain with four trophic levels,what would be the energy in the top trophic level if the energy contained in the primary producer level is 40,000 kcal/m2/yr? Assume a trophic level transfer efficiency of 10%.

Accepted Answer

A) 4,000 kcal/m2/yr 
B) 400 kcal/m2/yr 
C) 40 kcal/m2/yr 
D) 4 kcal/m2/yr 
E) 0.4 kcal/m2/yr

Question 20

Experimental studies with watersheds,such as the one of Hubbard Brook,show that trees and shrubs in an undisturbed ecosystem will help in

Accepted Answer

A) losing nutrients. 
B) retaining the nutrients. 
C) secondary productivity. 
D) being used as fire wooD. 
E) reducing the pollution.

Exam 58: Dynamics of Ecosystems

Choose the letter of the best match from the following: -Organisms are interrelated;energy transfers through the various trophic levels;there are a low number of herbivores,which are supported by much larger numbers of photosynthesizers.