Section 5.2 Practice

The process in which nitrogen is cycled between the atmosphere, bacteria, and other organisms is called

• phosphorus cycle
• nitrogen cycle
• oxygen cycle
• carbon cycle

_________________ break down decaying organisms.

• algae
• decomposers
• producers
• consumers

Which of the following is one of the largest carbon reservoirs on Earth?

• Limestone
• Amazon Rain Forest
• fossil fuels
• Atlantic Ocean

Producers convert _____________ in the atmosphere into carbohydrates during photosynthesis.

• oxygen
• carbon dioxide
• nitrous oxide
• phosphorus

Carbon molecules may form deposits of coal, oil, or natural gas, which are also known as __________________

• sinkholes
• greenhouse gases
• limestone pockets
• fossil fuels

Nitrogen makes up _____% of the gases in the atmosphere.

• 21%

• 35%

• 78%

• 89%

Plants absorb phosphates in the soil through their ___________

• leaves
• stems
• chloroplasts
• roots

Phosphorus may enter soil and water when rocks ______

• build up
• oxidize
• erode
• evaporate

Excessive amounts of fertilizer can enter terrestrial and aquatic ecosystems through _________________

• runoff
• evaporation
• transpiration
• photosynthesis

Excess nitrogen and phosphorus can cause rapid ________________________________.

• dehydration of plants
• algae growth
• deforestation
• cellular respiration