Unit 3 Ecosystems L.3.1, L.3.2, L.3.3

Which of these organisms is a producer in a marine ecosystem? 

• fish
• gull
• algae
• worm

What happens to a population and to competition when there is a reduction of living space?

• The population expands and competition intensifies 
• Competition strengthens while the population contracts.
• The population increases as competition decreases 
• Competition weakens and the population decreases 

Which BEST determines the number of wolves that can live in an area? 

• the amount of snow in the area each year
• the number of birds that live in the area
• the number of trees in the area
• the amount of food available in the area

Kudzu vines grow by climbing and wrapping around trees. Trees covered by kudzu can die because they are starved of sunlight. What type of relationship exists between the tree and the kudzu growing on them?

• competition
• mutualism
• parasitism
• predator-prey

Where is the largest amount of energy in a food web?

• hawk
• grass
• mouse
• grasshopper

Which BEST explains the importance of nitrogen in the cycling of energy and matter?

• Nitrogen increases protein production in plants.
• Nitrogen decreases protein production in plants.
• Nitrogen decreases the effectiveness of photosynthesis.
• Nitrogen increases the effectiveness of photosynthesis.

If wolves prey on deer for food, what will MOST LIKELY happen to the deer population  if wolves are removed from an area where deer live?

• The population of deer will increase
• The population of deer will decrease.
• The population of deer will remain the same.
• The population of deer will become extinct.

Where do plants get most of the energy they need to live and grow?

• water
• soil
• air
• sunlight

In a food pyramid, which BEST explains why the number of organisms decreases from one trophic level to the next?

• Consumers at the lower level require more energy than the top-level consumers.
• Consumers at the top level require more energy than the lover-level consumers.
• The consumers are feeding on larger organisms that have less energy.
• The consumers are feeding on smaller organisms that have less energy.