Unit Cycle

Which of the following is NOT one of the three main nutrient cycles studied in ecosystems?

• Oxygen cycle

• Water (Hydrologic) cycle

• Carbon cycle

• Nitrogen cycle

Which group(s) are at risk due to the harmful algal bloom in Lake Lowell?

• Only humans

• Only animals

• Both humans and animals

• Only fish

Which process in the carbon cycle involves plants taking in carbon dioxide from the atmosphere?

• Photosynthesis

• Animal respiration

• Root respiration

• Transportation emissions

What is the main topic illustrated in the provided diagram?

• The Nitrogen Cycle

• The Water Cycle

• The Carbon Cycle

• The Oxygen Cycle

Explain how photosynthesis and cellular respiration are connected in the carbon cycle.

• Photosynthesis releases CO₂, which is used in cellular respiration.

• Cellular respiration captures CO₂, which is used in photosynthesis.

• Photosynthesis captures CO₂ to make sugar, and cellular respiration releases CO₂ back into the atmosphere.

• Both processes only occur in animals.

In what form is nitrogen found in the atmosphere?

• N₂

• NH₄⁺

• NO₃⁻

• NO₂⁻

Which process is primarily responsible for returning water vapor to the atmosphere in the water cycle?

• Condensation

• Evaporation

• Precipitation

• Infiltration

What role do decomposers play in nutrient cycles?

• They release oxygen during photosynthesis.

• They fix atmospheric nitrogen into usable forms.

• They break down dead organisms, returning nutrients to the soil.

• They absorb water from the soil.

Which of the following is a consequence of increased carbon dioxide in the atmosphere?

• Increased rainfall

• Decreased plant growth

• Global warming

• Reduced oxygen levels

What role do bacteria play in the nitrogen cycle?

• Bacteria only decompose organic matter in the nitrogen cycle.
• Bacteria are not involved in any processes related to nitrogen.
• Bacteria primarily consume nitrogen without transforming it.
• Bacteria are essential for nitrogen fixation, nitrification, and denitrification in the nitrogen cycle.