Carbon and nitrogen cycle

Question 1

What is the primary gas that exists in the atmosphere as part of the carbon cycle?

Answer 1

Carbon dioxide (CO2)

Carbon dioxide is a critical component of the carbon cycle, influencing both plant growth and climate.

Question 2

What process do plants and algae use to take in carbon dioxide from the atmosphere?

Answer 2

Photosynthesis

Photosynthesis converts carbon dioxide and water into glucose and oxygen using sunlight.

Question 3

What are some carbon compounds that are produced by plants during photosynthesis?

Answer 3

• Glucose
• Amino acids
• Cellulose

These compounds are essential for plant structure and function.

Question 4

How is carbon transferred from plants to animals in the carbon cycle?

Answer 4

Through feeding

Animals assimilate carbon by consuming plants and incorporating it into their own bodies.

Question 5

What process do plants and animals use to return carbon to the atmosphere?

Answer 5

Respiration

Respiration converts glucose and oxygen back into carbon dioxide and water, releasing energy.

Question 6

What happens to carbon when plants and animals die?

Answer 6

Decomposers break them down, releasing carbon dioxide

Decomposition is a key process in recycling carbon back into the atmosphere.

Question 7

What is the fate of organisms that become fossilized?

Answer 7

They can form fossil fuels

Fossil fuels release carbon dioxide into the atmosphere when burned.

Question 8

What is the role of decomposers in the carbon cycle?

Answer 8

They break down dead organic matter and release carbon dioxide

Decomposers are essential for nutrient recycling in ecosystems.

Question 9

What is extracellular feeding?

Answer 9

A process where digestive enzymes are secreted to break down insoluble materials

This allows organisms to absorb nutrients from their environment.

Question 10

What environmental condition is necessary for enzymes involved in digestion to function properly?

Answer 10

The right temperature

Enzymes can denature if temperatures are too high, affecting digestion.

Question 11

What role does water play in the digestion process?

Answer 11

It helps dissolve materials

Water is crucial for facilitating the absorption of nutrients.

Question 12

Fill in the blank: The process by which plants convert carbon dioxide into glucose is called _______.

Answer 12

photosynthesis

This process is fundamental for life on Earth as it produces energy-rich compounds.

Question 13

True or False: Carbon is only found in living organisms and not in the atmosphere.

Answer 13

False

Carbon exists in both the atmosphere and in organic compounds within living organisms.

Question 14

What do decomposers need to respire?

Answer 14

Oxygen

Decomposers require oxygen for the process of respiration, which is essential for decomposition.

Question 15

In what conditions does decomposition work the fastest?

Answer 15

Wet, warm and oxygenated conditions

The rate of decomposition is influenced by environmental factors such as moisture, temperature, and oxygen availability.

Question 16

What is the main gas involved in the nitrogen cycle?

Answer 16

Atmospheric nitrogen (N₂)

Nitrogen gas is abundant in the atmosphere and plays a crucial role in the nitrogen cycle.

Question 17

Which bacteria convert nitrogen gas into ammonia?

Answer 17

Nitrogen-fixing bacteria

These bacteria can be found in root nodules and soil, facilitating the conversion of atmospheric nitrogen into a usable form.

Question 18

What do nitrogen-fixing bacteria convert nitrogen into?

Answer 18

Ammonia

This process is essential for creating amino acids and proteins necessary for plant and animal life.

Question 19

What ions are produced from the decomposition of proteins?

Answer 19

Ammonium ions (NH₄⁺)

Bacteria and fungi break down organic matter, returning nitrogen to the soil in the form of ammonium ions.

Question 20

What process do nitrifying bacteria perform?

Answer 20

Nitrification

Nitrifying bacteria oxidize ammonia to produce nitrites and then nitrates, which are essential nutrients for plants.

Question 21

How do lightning strikes contribute to the nitrogen cycle?

Answer 21

They convert nitrogen gas into nitrogen oxides

This conversion allows nitrogen to be deposited into the soil via rainwater.

Question 22

What process allows plants to absorb nitrates from the soil?

Answer 22

Active transport

Plants utilize energy to actively take up nitrates from the soil for their growth.

Question 23

What do denitrifying bacteria convert nitrates into?

Answer 23

Nitrogen gas

This process returns nitrogen gas to the atmosphere, completing the nitrogen cycle.