Ecosystem Dynamics Practice

The ozone layer, which filters out about 95% of the sun’s harmful UV radiation, is found in the ___.

• Stratoshere

• Bioshpere

• Geosphere

• Troposphere

In the biosphere, ___.

• Trees emit oxygen and animals consume oxygen

• Both trees and animals emit oxygen

• Animals emit oxygen and trees consume oxygen

• Animals both emit and consume carbon dioxide

Cows eating grass are categorized as which trophic level?

• Producer

• Primary consumer

• Secondary consumer

• Tertiary consumer

Organisms that feed on the wastes or dead bodies of other organisms are best described as ___.

• Omnivores

• Herbivores

• Carnivores

• Detritivores

With each transfer of energy from one trophic level to the next, about ___ of the energy is lost.

• 90%

• 50%

• 20%

• 10%

When precipitation reaches a land surface, it can either result in infiltration that replenishes groundwater or in ___ that ends up in lakes and rivers.

• Runoff

• Respiraton

• Transpiration

• Condensation

Humans are altering the carbon cycle by ___.

• Killing off large numbers of animals, which reduces the amount of carbon in the system

• Growing crops, which increases the amount of carbon in the system

• Burning fossil fuels, which adds carbon dioxide to the atmosphere

• Extracting fossil fuels from the ground, which removes carbon from the system

Mathematical models can be useful for researching ecosystems that are otherwise difficult to study, such as ___.

• A simple system that has only one variable

• A large-scale natural system such as the Great Lakes

• A complex system that has no variables

• A medium-scale system such as a pond

Because Earth does not get significant inputs of matter from space, its essentially fixed supply of nutrients must continually be recycled to support life.

• True

• False

It is easier to carry out a controlled experiment in the field, as opposed to in the laboratory.

• True

• False