Cycles of Matter in Ecosystems Part 2: Carbon, Phosphorus, Oxygen, and Water

Multiple Choice

Why is it important to understand the cycles of matter such as carbon, phosphorus, oxygen, and water in ecosystems?

• Because they help us understand how nutrients move and support life

• Because they determine the color of plants

• Because they are only important for scientists to understand how solar radiation affects Earth.

• Because they have no impact on the environment, unless there is climate change.

Multiple Choice

What happens to carbon in organisms when they die?

• It is released as carbon dioxide or stored as fossils.

• It disappears completely.

• It turns into water vapor (water gas).

• It is only used by plants.

Multiple Choice

Which process in the carbon cycle is responsible for converting carbon dioxide into sugars using sunlight?

• Photosynthesis

• Respiration

• Decomposition

• Combustion

Multiple Choice

What happens to carbon when living things die and decay?

• It is broken down and released as CO2 by bacteria or fungi.

• It disappears completely from the environment.

• It turns directly into fossil fuels immediately.

• It is only stored in plants.

Multiple Choice

According to the diagram, what process removes carbon dioxide from the atmosphere?

• Photosynthesis

• Combustion

• Decomposition

• Respiration

Multiple Select

Which of the following are ways carbon can return to the atmosphere as shown in the carbon cycle diagrams?

• Combustion of fossil fuels

• Cellular respiration

• Photosynthesis

• Decomposition

Multiple Choice

What is the main purpose of carbon sequestration as shown in the diagram?

• To store carbon in the soil and plants

• To increase carbon dioxide in the atmosphere

• To speed up fossil fuel formation

• To reduce plant growth

Multiple Choice

Which of the following best describes the role of plants in carbon sequestration within the soil food web?

• Plants absorb carbon from the atmosphere and help store it in the soil through their roots and interactions with other organisms.

• Plants release all the carbon they absorb back into the atmosphere immediately.

• Plants do not play any role in carbon sequestration.

• Plants only store carbon in their leaves, not in the soil.

Multiple Select

Which of the following are steps in the phosphorus cycle as described in the rock cycle explanation?

• Reservoir (storage in rocks and sediments)

• Assimilation (absorption by plants and animals)

• Release (decomposition and excretion)

• Photosynthesis (conversion of sunlight to energy)

Multiple Choice

During the oxygen cycle, what do animals and other organisms take in from the air?

• Oxygen

• Carbon dioxide

• Nitrogen

• Hydrogen

Multiple Choice

Which process in the water cycle involves water moving from the surface of plants to the atmosphere?

• Evapotranspiration

• Precipitation

• Runoff

• Percolation