CYCLES REVIEW 3

If humans replace the forest with a factory, how will this affect the carbon cycle in the area?

• The forest is defined as a carbon sink, and with its removal, there will be less carbon released into the atmosphere.

• The forest is defined as a carbon source, and with its removal, there will be less carbon released into the geosphere.

• The forest is defined as a carbon sink, and with its removal, there will be more carbon released into the atmosphere.

• The forest is defined as a carbon source, and with its removal, there will be more carbon released into the hydrosphere.

Which statement about the cycling of materials through a stable ecosystem is true?

• Certain species of bacteria are responsible for cycling nitrogen from the atmosphere to plants.

• Carbon dioxide is continuously cycled through a stable ecosystem, but only bacteria can convert it to a usable form.

• Radiant energy and heat are continuously recycled from animals to plants.

• Water and energy are the only materials in an ecosystem that cannot be recycled.

The diagram shows the water cycle. When are impurities such as dust and particulates removed from the atmosphere?

• during Condensation and Precipitation

• during Evaporation and Transpiration

• during Runoff and Precipitation

• during Condensation and Evaporation

Nutrients are continually reused and flow through an ecosystem from organism to organism. Refer to the diagram showing the nutrient cycle with producers, consumers, and soil nutrients. What is a specific example of an organism that could be represented by the letter X on the nutrient cycle?

• bacteria

• deer

• ferns

• lions

A diagram outlining the phosphorus cycle in an ecosystem is shown. If the amount of phosphates present in water increased, what would be the most direct effect on the ecosystem?

• It will result in a decrease of phosphates in animal tissues and wastes.

• It will result in a decrease in the weathering of rocks.

• It will result in an increase in the rate of decomposition by bacteria and fungi.

• It will result in an increase in the incorporation of phosphates into sedimentary rocks.

The diagram shows the cycling of nitrogen through an ecosystem. If the number of denitrifying bacteria decreased, what direct effect would this have on the ecosystem?

• More nitrogen would be available for leguminous plants.

• Less nitrate ions would be available for assimilation in plants.

• Less nitrogen would be available for fixation by nitrogen-fixing soil bacteria.

• More ammonium ions would be available for nitrification by nitrifying bacteria.

Carbon dioxide concentrations have been monitored on a monthly basis for almost 60 years in a mountain ecosystem in Hawaii. The data and its trends are shown in the graph.

• acid precipitation

• anaerobic respiration

• global warming

• ozone depletion

The diagram depicts the movement of carbon through the environment. According to the diagram, which statement is correct concerning the interaction between carbon dioxide and living things?

• Plants release carbon dioxide into the atmosphere as they produce sugars and starches.

• Plants use carbon dioxide from the atmosphere as they produce sugars and starches.

• Animals release carbon dioxide into the atmosphere as they produce sugars and starches.

• Animals use carbon dioxide from the atmosphere as they produce sugars and starches.

Use the diagram to answer the question. As human population growth continues, humans are searching for more places to create habitats. This includes cutting down vast numbers of trees to clear land on which to build. According to the diagram, which statement best represents how deforestation will impact the carbon cycle?

• The rate of photosynthesis will increase, positively impacting the cycle.

• The rate of photosynthesis will decrease, positively impacting the cycle.

• The rate of photosynthesis will decrease, negatively impacting the cycle.

• The rate of photosynthesis will increase, negatively impacting the cycle.

Phosphorus is one of the most abundant elements found in living organisms. It is also an essential element for the survival of green plants. What would be the consequence of the excessive deposition of phosphate-containing fertilizers into a lake?

• Land animals would die off due to the lack of phosphates.

• Phosphate sediments would not form at the bottom of the lake.

• Algae in the lake would multiply rapidly, causing an algal bloom.

• Decomposers would decrease in number due to increased phosphate levels.