ETIABO: Nutrient cycles- Nitrogen Cycle

Question 1

Plants mainly absorb nitrogen in the form of _____.

Answer 1

Nitrate

Question 2

Name the products that form as nitrogen gas turns into nitrate:

Answer 2

• Nitrogen gas
• Ammonium ions
• Nitrite
• Nitrate

Question 3

How do animals get nitrates from plants?

Answer 3

They consume the plants

Question 4

What 2 places is the bacteria needed to process nitrogen found?

Answer 4

• Soil
• Specific plant roots

Question 5

How is nitrogen gas converted into ammonium ions through free-living nitrogen-fixing bacteria found in the soil?

Answer 5

• Free-living nitrogen-fixing bacteria in the soil converts nitrogen gas into ammonia.
• The bacteria releases this ammonia into the soil where it dissolves in water.
• This forms ammonium ions

Question 6

How does nitrogen fixation work?

Answer 6

• The mutualistic nitrogen-fixing bacteria in specific plant’s roots converts nitrogen gas into ammonia.
• The ammonia is used by the plant.
• The bacteria gains carbohydrates from the plant.

Question 7

What is the name of bacteria found in soil?

Answer 7

Free-living nitrogen-fixing bacteria

Question 8

What is the name of bacteria found in specific plant roots?

Answer 8

Mutualistic nitrogen-fixing bacteria

Question 9

What does mutualistic nitrogen-fixing bacteria do?

Answer 9

• It is found in the roots of specific plants and converts nitrogen gas into ammonia.
• This ammonia is used by the plant.
• (In return) The bacteria gains carbohydrates from the plant

Question 10

What does free-living nitrogen-fixing bacteria do?

Answer 10

• It is found in soil and converts nitrogen gas into ammonia.
• The bacteria releases this ammonia into the soil where it dissolves in water.
• This forms ammonium ions

Question 11

What are the two types of nitrogen-fixing bacteria?

Answer 11

Free-living nitrogen-fixing bacteria
Mutualistic nitrogen-fixing bacteria

Question 12

The process of converting nitrogen gas into ammonia is known as ______-_______.

Answer 12

Nitrogen-fixing

Question 13

In the soil ammonia is converted into ______.

Answer 13

Ammounium ions

Question 14

What happens in nitrification?

Answer 14

• Ammonium ions turn into nitrite
• Nitrite turns into nitrate.

Question 15

What is the name of the bacteria that carry out nitrification?

Answer 15

Nitrifying bacteria

Question 16

Nitrifying bacteria need _____ to work.

Answer 16

Oxygen

Question 17

What are the 2 reasons why nitrifying bacteria need oxygen to work?

Answer 17

1) Needed for aerobic respiration
2) Used in nitrification

Question 18

How does dead organic matter and excretion impact the nitrogen cycle?

Answer 18

• Waste is fed on by sacrobionts.
• Nitrogen-containng compounds, like DNA, is broken down into ammonia
• Ammonia in the soil is dissolved in water and forms ammonium ions (ammonification).

Question 19

What happens in ammonification?

Answer 19

• Waste is fed on by sacrobionts.
• Nitrogen-containng compounds, like DNA, is broken down into ammonia
• Ammonia in the soil is dissolved in water and forms ammonium ions.

Question 20

Ammonification helps replenish the amount of _________ in the soil.

Answer 20

Ammonium ions

Question 21

Describe 2 of the roles of saprobionts:

Answer 21

• Saprobionts break down nitrogen-containing compounds, such as DNA and amino acids.
• This break down produced ammonium ions.

Question 22

Nitrogen-containing compounds in waste are broken down by ______ to form ammonia.

Answer 22

Saprobionts

Question 23

What happens in denitrifcation?

Answer 23

Nitrate in the soil is converted into nitrogen gas through denitrifying bacteria anaerobically respiring.

Question 24

What is the name of bacteria involved in denitrifcation?

Answer 24

Denitrifying bacteria

Question 25

The process of converting nitrate to nitrogen gas is known as _______.

Answer 25

Denitrifcation

Question 26

The process of converting nitrate to nitrogen gas is known as _______.

Answer 26

Nitrification

Question 27

Denitrification occurs when denitrifying bacteria carry out _______ respiration.

Answer 27

Anaerobic

Question 28

What 2 biological molecules do plants from nitrate?

Answer 28

- Amino acids - Nucleic acids

Question 29

Which two processes produce ammonium ions in the nitrogen cycle?

Answer 29

- Nitrogen fixation - Ammonification

Question 30

The relationship between the roots and fungi is known as ________.

Answer 30

Mycorrhizae

Question 31

What are the two benefits of mycorrhizae:

Answer 31

- Increases the roots SA for water and mineral intake- increasing the plants chance of survival. - The fungi acts as a sponge and holds onto water- especially helpful if there is a drought.

Question 32

In mycorrhizae what does the fungi receive from the plant?

Answer 32

Products of photosynthesis