Natural systems

Question 1

What are systems made up of?

Answer 1

• Stores
• Flows
• Boundries
• Inputs
• Outputs

Question 2

What are inputs?

Answer 2

When matter (a physical substance like water or carbon) is added to a system.

Question 3

What are outputs?

Answer 3

When matter or energy leaves a system.

Question 4

What are stores?

Answer 4

Where matter or energy builds up.

Question 5

What are flows/transfers?

Answer 5

When matter or energy moves from one store to another.

Question 6

What are boundries?

Answer 6

The limits of a system.

Question 7

How is a drainage basin an example of a system?

Answer 7

• Water enters the system as rain (input).
• The systems watershed is the boundry.
• Some of the water is stored in soil + vegetation.
• Water travels from the drainage baisin to the river and down the river (flow).
• Water leaves the system where the river meets the sea (output).

Question 8

What are the different types of systems?

Answer 8

• Open
• Closed

Question 9

What can open systems have?

Answer 9

Energy and matter can enter and leave an open system and there are inputs and outputs of both.

Question 10

What is an example of an open system?

Answer 10

Drainage baisins as energy from the sun enters and leaves the system, the water is the input as precipitation and output is the river discharge into the sea.

Question 11

What are closed systems?

Answer 11

When energy inputs = outputs.

Question 12

What happens to matter in closed systems?

Answer 12

It cycles between stores as matter (physical substance such as water/carbon) can’t enter of leave a closed system.

Question 13

What happens to energy in closed systems?

Answer 13

Energy can enter and leave a closed system and can be input or output.

Question 14

What is an example of a closed system?

Answer 14

The carbon cycle is a closed system as energy is input (eg, the sun through photosynthesis) and output (eg, by respiration) but the amount of carbon on the earth stays the same as there are no inputs or outputs of matter.

Question 15

What does it mean for a system to be in equilibrium?

Answer 15

Inputs = Outputs despite changing conditions.
Flows and processes can continue to happen but in the same way so there is no overall changes to the system.

Question 16

How are systems affected by feedback?

Answer 16

• If the inputs and outputs of a system are balanced the system is in equilibrium.
• But within systems there are small variations in the inputs and outputs of systems (such as the amount of precipitation entering a river) but they tend to be very small so the inputs/outputs remain balanced. - This means the system is in dynamic equilibrium.
• Large, long term changes to the balance of inputs and outputs can cause the system to change and establish a new dynamic equilibrium.

Question 17

What happens if there are changes within a system?

Answer 17

A positive or negative feedback may be triggered.

Question 18

What does positive feedback do?

Answer 18

Amplify the change in inputs or outputs which means the system responds by increasing the effects of the change which moves the system moves further away it’s previous state.

Question 19

What is an example of a positive feedback?

Answer 19

• Temperatures rise
• Ice covering the cold parts of earth melts as there are higher temperatures
• Less ice cover so less of the Sun’s energy is reflected
• Due to less energy being reflected more heat is absorbed by the earth.

Question 20

What does negative feeback do?

Answer 20

They counteract the change in the inputs or outputs so the system responds through decreasing the effects of change and thus keeping the sytem closer to dynamic equilibrium.

Question 21

What is an example of negative feedback?

Answer 21

• Large amount of CO2 emitted
• CO2 increases in the atmosphere
• Extra CO2 causes plants to grow
• Plants remove and store CO2 through photosynthesis
• Amount of CO2 in atmosphere decreases.

Question 22

What type of system is the earth?

Answer 22

The earth can be seen as a closed system as energy is an input from the sun and then output to space but matter is not input or output to space. The earth is broken down into subsytems to explain further systems.

Question 23

What are the subsytems in earth?

Answer 23

• Cyrosphere
• Lithosphere
• Biosphere
• Hydrosphere
• Atmosphere

Question 24

What is the cyrosphere?

Answer 24

The cyrosphere includes all parts of the Earth system where it’s cold enough for water to freeze such as glacial landscapes.

Question 25

What does the lithosphere include?

Answer 25

The lithosphere is the outermost part of the earth and it includes the crust and upper parts of the mantle.

Question 26

What does the biosphere include?

Answer 26

The biosphere is the part of the Earths system where living things are found and include all living parts of the earth such as plants, animals, bacteria etc.

Question 27

What does the hydrophere include?

Answer 27

Includes all water on earth and it may be in liquid form (such as lakes), solid form (like ice) or gas (water vapour). It may also be saline (salty) or fresh.

Question 28

How are subsytems within earth linked?

Answer 28

They are all interlinked by the cycles and processes that keep the earth’s overall system running normally.

Question 29

What happens with matter in sub systems?

Answer 29

Matter and energy can move between the subsytems - the output of one cycle is the input of the next and then the output of one cycle is the input of the next etc.

Question 30

Why is the earth a cascading system?

Answer 30

Becuase all matter and energy move from one subsystem to the next and the changes in one sub sytem can affect the next.

Question 31

What may happen if changes occur in one subsytem?

Answer 31

Changes in one subsytem may lead to changes in the other one and can affects what happens.