TROPHIC LEVELS

 
^{_{In the food pyramid above, which of the following organisms are herbivores?}}

• (A) humans 
• (B) fish 
• (C) minnows 
• (D) copepods 

_{Grass → Cricket → Prairie chicken → Coyote → Vulture}
In which organism in the food chain above would be the biological magnification of DDT concentration be most obvious?
(A) grass
(B) cricket
(C) prairie chicken
 (D) coyote 

• A
• B
• C
• D

Which of the following is true about secondary consumers in an ecosystem?

• A) They eat only plants.
• B) They are eaten by primary consumers
• C) They are smaller and weaker than are primary consumers. 
• D) They are fewer in number than are primary consumers.

What brings back atmospheric Carbon back into organic molecules? 

• Autotrophs
• Heterotrophs
• Little Gremlins who steal the oxygen  
• Decomposers

In the nitrogen cycle, the transformation of gaseous nitrogen into nitrogen-containing compounds is performed primarily by  

• (A) fungi 
• (B) bacteria
• (C) green plants 
• (D) herbivores

Which of the following best explains why there are seldom more than five trophic levels in a food chain?  

•  Trophic levels above this number contain too many individuals.
• Top carnivores are too few in number to prey effectively 
•  The ecosystem contains too much biomass. 
• Energy is lost from each trophic level.

 All of the following statements about the pyramid of biomass are correct EXCEPT 

• (A) Biomass is the total dry mass of the organisms present. 
• (C) Biomass pyramids tend to vary for different ecosystems.
• (B) The base of the pyramid generally represents primary consumers. 
•  (D) Certain toxins tend to become concentrated at upper levels of the pyramid. 

The carbon cycle is driven by what?

• The Sun
• The Plants
• The animals
• HUMANS

How does organic carbon return into the atmosphere?

• Through cellular respiration in animals
• Through photosynthetic plants
• Through oxygen
• Through water

How does organic carbon return into the atmosphere?

• Through cellular respiration in animals
• Through photosynthetic plants
• Through oxygen
• Through water