Nitrogen cycle

What is the process by which atmospheric nitrogen is converted into a form used by living organisms?

• Nitrogen transformation

• Nitrogen absorption

• Nitrogen fixation

• Nitrogen decomposition

What type of bacteria are responsible for the fixation of atmospheric nitrogen?

• Rhizobium and Azotobacter

• Escherichia coli

• Streptococcus

• Salmonella

What process converts organic nitrogen compounds into ammonia?

• Fermentation

• Decomposition

• Deamination

• Nitrification

What type of bacteria convert ammonia into nitrites and then into nitrates?

• Decomposer bacteria

• Photosynthetic bacteria

• Anaerobic bacteria

• Nitrifying bacteria

What process converts nitrates into gaseous nitrogen?

• Decomposition

• Nitrosation

• Nitrification

• Denitrification

What role do plants play in the nitrogen cycle?

• Plants absorb oxygen from the soil and convert it into nitrogen

• Plants absorb nitrates from the soil and convert them into proteins, releasing nitrogen back into the soil when they die.

• Plants have no relationship with the nitrogen cycle

• Plants release nitrogen into the air during their photosynthesis process

What happens to the nitrogen in the soil when plants and animals die?

• It accumulates in the soil unchanged

• It is converted into oxygen

• It is directly absorbed by plants

• It is released through the decomposition of organic matter by microorganisms.

What type of bacteria decompose organic matter releasing ammonia into the soil?

• Decomposer bacteria

• Nitrogen-fixing bacteria

• Nitrifying bacteria

• Fermenting bacteria

What process converts ammonia into nitrates in the soil?

• Photosynthesis

• Nitrification

• Fermentation

• Denitrification

Why is the nitrogen cycle important for ecosystems?

• The nitrogen cycle only affects a small part of ecosystems

• The nitrogen cycle is important for ecosystems because it is an essential element for the life of plants and other organisms, allowing the formation of proteins and genetic material.

• The nitrogen cycle has no impact on ecosystems

• Ecosystems can survive without the nitrogen cycle