CFA AKS 13 Review

Producers release carbon dioxide during

• cellular respiration

• photosynthesis

• transformation

• decomposition

In order for plants and animals to be able to use nitrogen, N2 gas must first be converted to more a chemically available form. Review the picture of the nitrogen cycle. One type of organism is responsible for "fixing" nitrogen so other organisms can use the element. What organism is this?

• animals

• bacteria

• plants

• fungi

An energy pyramid is a graphical model of energy flow in a community. The different levels represent different groups of organisms that compose a food chain. An energy pyramid’s shape shows how the amount of useful energy that enters each level. Chemical energy, in the form of food, decreases because some is used by the organisms in each level. The source of the chemical energy is the producers. Producers rearrange carbon dioxide and water in the presence of light to make ________ through the process of ______________.

• sugars; photosynthesis

• oxygen; respiration

• energy; photosynthesis

• sugars; respiration

The fungi in the picture are an important part of any ecosystem because they

• use sunlight to make food for other organisms.

• break down dead organisms and recycle nutrients.

• add oxygen to the atmosphere.

• are important producers for consumers in the food web.

A tiny rocky island in the South Pacific is home to a very small food chain. Coconut palms grow on the island and drop coconuts. The coconuts are eaten by coconut crabs. The coconut crabs are then eaten by seals. According to an ecological energy pyramid, the seals would receive about ___________ of the energy from the coconuts.

• 10%

• 1%

• 100%

• 0.1%

CO2 is not returned to the atmosphere by

• respiration

• photosynthesis

• decomposition

• combustion

An ecological pyramid is sometimes used to show both the flow of matter and energy in an ecosystem. The pyramid narrows as matter and energy flow from the bottom to the top. Draw a conclusion about what this pyramid tells you about the energy in this ecosystem.

• Energy increases from bottom to top because the organisms get larger in size.

• Energy stays the same. Only the number of living things change.

• Energy decreases from bottom to top because some is used at each level for life processes.

• Energy decreases from the top to the bottom as organisms are larger in size.

Which organism would be the main source of oxygen in a forest ecosystem?

• lichens

• ants

• mushrooms

• oaktrees

What are two processes of the carbon cycle?

• cellular respiration and transpiration

• transpiration and transport

• cellular respiration and photosynthesis

• photosynthesis and transport

Only part of the energy in one trophic level gets passed to the next level. In any energy pyramid, about _____________ is passed from level to level.

• 30%

• 25%

• 5%

• 10%