Biogeochemical Cyc

What is the primary gas that makes up around 0.04% of the gases in our atmosphere and is also the backbone of the most important biological molecules?

• Oxygen

• Nitrogen

• Carbon dioxide

• Methane

During photosynthesis, what do plants and algae use to produce glucose?

• Oxygen

• Nitrogen

• Carbon dioxide

• Methane

What process releases carbon dioxide back into the atmosphere from animals and plants?

• Photosynthesis

• Aerobic cellular respiration

• Fossilization

• Combustion

Under certain conditions, what can happen to an organism after it dies that can take thousands or even millions of years?

What do humans extract from the earth and burn, which then converts into carbon dioxide and enters our atmosphere?

• Water vapor

• Nitrogen

• Oxygen

• Fossil fuels

How do marine life such as molluscs and crustaceans use carbon dioxide?

What percentage of the air we breathe is made up of nitrogen?

• 21%

• 78%

• 55%

• 10%

Which process converts nitrogen into ammonium ions (NH4+)?

• Nitrification

• Nitrogen fixation

• Assimilation

• Ammonification

What is the role of Nitrosomonas in the nitrogen cycle?

• They convert nitrogen gas into nitrates.

• They convert ammonium ions into nitrites.

• They convert nitrites into nitrates.

• They fix nitrogen from the atmosphere.

Which bacteria are responsible for converting nitrites into nitrates?

• Nitrosomonas

• Nitrobacter

• Rhizobium

• Decomposers