Community Ecology II

Which statement about Net Primary Productivity is CORRECT?

• It is measured as energy fixed per unit area.

• It is the total biomass gained by heterotrophic organisms per unit time.

• It is equivalent to the total solar energy fixed by photosynthesis in green plants.

• It is the gain in energy or biomass per unit area per unit time after allowing for loss through respiration.

Which of the following best explains the need for a constant influx of sunlight to sustain Earth's biosphere?

• energy from sunlight moves through ecosystems but is lost as heat

• energy from sunlight warms the Earth, which allows organisms to flourish

• energy from sunlight is the primary source of chemical energy

• energy from sunlight strikes Earth and is recycled through food webs

Which of the following components is not recycled within an ecosystem?

(a)  

• heat
• nitrogen
• phosphorus
• carbon

Which of the following best represents the actions of photoautotrophs?

• produce oxygen and use carbon dioxide

• produce, and use, both oxygen and carbon dioxide

• produce thermal energy to be used by other organisms

• convert chemical energy to solar energy

The wavy arrow exiting the left side of the "Primary consumers" box could best be described as which of the following examples of a nutrient transfer?

• decomposition of dead matter

• feces excreted by the primary consumer

• predation of the primary consumer

• production consumed by the primary consumer

Which of the following most accurately describes the fate of incoming solar radiation from the sun?

• Most of the incoming solar radiation is transmitted through plant leaves or lost as heat.

• A tiny fraction of the incoming solar radiation is absorbed by photosynthetic plant pigments.

• Most incoming solar radiation strikes and is absorbed by Earth's land surfaces.

• Solar radiation is least intense at the tropics.

Which of the following terms encompasses all of the others?

(a)  

• heterotrophs
• herbivores
• carnivores
• primary consumers

In the figure, the jagged arrow leaving microorganisms and other detritivores represents which process?

• organic compounds broken down by bacteria

• energy consumed by bacteria

• energy lost from a worm during cellular respiration

• CO2 and heat loss from detritus due to solar radiation and precipitation

In the ecosystem figure, which component of the food web has the potential to lose the most energy as heat?

• secondary and tertiary consumers

• primary consumers

• primary producers

• microorganisms and other detritivores

Which habitat type in the figure covers the largest area?

(a)  

• tropical wet forest
• rock, sand, ice
• algal beds and reefs
• open ocean