Biogeochemical Cycles Assessment

Which process in the water cycle involves water changing from a liquid to a gas?

• Condensation

• Evaporation

• Precipitation

• Infiltration

Answer explanation

The process in the water cycle where water changes from a liquid to a gas is called evaporation. During evaporation, heat energy causes liquid water to transform into water vapor, rising into the atmosphere.

Tags

NGSS.MS-ESS2-4

NGSS.MS-PS1-4

What is the main form of nitrogen found in the atmosphere?

• Ammonia

• Nitrite

• Nitrogen gas

• Nitrate

Answer explanation

The main form of nitrogen in the atmosphere is nitrogen gas (N2), which makes up about 78% of the air we breathe. Ammonia, nitrite, and nitrate are other nitrogen compounds but are not predominant in the atmosphere.

Which element is cycled through the process of photosynthesis and respiration?

• Sulfur

• Phosphorus

• Carbon

• Nitrogen

Answer explanation

Carbon is the key element cycled through photosynthesis and respiration. In photosynthesis, plants convert carbon dioxide into glucose, while in respiration, organisms release carbon dioxide back into the atmosphere.

Tags

NGSS.MS-LS1-6

Which process returns carbon dioxide to the atmosphere during the carbon cycle?

• Photosynthesis

• Respiration

• Nitrogen fixation

• Precipitation

Answer explanation

Respiration is the process where organisms convert glucose and oxygen into energy, releasing carbon dioxide as a byproduct back into the atmosphere, thus playing a crucial role in the carbon cycle.

What is the main reservoir for phosphorus in the phosphorus cycle?

• The atmosphere

• Rocks and soil

• Oceans

• Living organisms

Answer explanation

The main reservoir for phosphorus in the phosphorus cycle is rocks and soil. Phosphorus is primarily stored in mineral form in the Earth's crust, which is then released into the soil and water through weathering.

Which process in the nitrogen cycle converts atmospheric nitrogen into a form usable by plants?

• Denitrification

• Nitrogen fixation

• Ammonification

• Nitrification

Answer explanation

Nitrogen fixation is the process that converts atmospheric nitrogen (N2) into ammonia (NH3), which plants can use for growth. This is essential for incorporating nitrogen into the ecosystem.

Which gas is released into the atmosphere during the decomposition of organic matter in the sulfur cycle?

• Oxygen

• Sulfur dioxide

• Nitrogen

• Carbon dioxide

Answer explanation

During the decomposition of organic matter, sulfur-containing compounds break down, releasing sulfur dioxide (SO2) into the atmosphere. This is a key part of the sulfur cycle, distinguishing it from other gases like carbon dioxide.

Which process in the carbon dioxide-oxygen cycle is performed by green plants?

• Respiration

• Photosynthesis

• Decomposition

• Combustion

Answer explanation

Green plants perform photosynthesis, a process that converts carbon dioxide and sunlight into oxygen and glucose, playing a crucial role in the carbon dioxide-oxygen cycle.

Tags

NGSS.MS-LS1-6

Explain how deforestation can impact the carbon cycle.

• It increases the rate of photosynthesis.

• It decreases the amount of carbon dioxide in the atmosphere.

• It reduces the number of trees that absorb carbon dioxide, increasing atmospheric carbon dioxide.

• It has no effect on the carbon cycle.

Answer explanation

Deforestation reduces the number of trees that can absorb carbon dioxide, leading to higher levels of carbon dioxide in the atmosphere. This disrupts the carbon cycle, contributing to climate change.

Tags

NGSS.MS-ESS3-4

NGSS.MS-LS2-3

Which of the following best describes the role of bacteria in the nitrogen cycle?

• They produce oxygen for plants.

• They convert nitrogen gas into forms plants can use.

• They break down rocks to release phosphorus.

• They absorb water from the soil.

Answer explanation

Bacteria play a crucial role in the nitrogen cycle by converting nitrogen gas from the atmosphere into ammonia and nitrates, which are forms that plants can readily use for growth.

Tags

NGSS.MS-LS2-3