Systems

Question 1

What is a system?

Answer 1

An assemblage of parts and their relationship forming a functioning entirety or whole (with inputs, processes and outputs)

Question 2

Gaia Hypothesis

Answer 2

• Developed in 1970’s by James Lovelock.

- States that the planet acts like a single biological being made up of individual and interconnected units.

Question 3

What are the 3 types of systems?

Answer 3

1. Open systems (exchange energy and matter with its surroundings).
2. Closed systems (exchange energy buy NOT matter with its surroundings).
3. Isolated System (exchanges neither energy nor matter) (Do not exist naturally). EG. The universe.

Question 4

Flows and Storage:

Answer 4

• Systems are made up of inputs, processes and outputs.
• They consist of energy and matter.
• We want to look at the stores and flows of energy and matter in a system.
• Energy and matter flow through ecosystems as inputs and outputs, and they are also stored within an ecosystem.

Question 5

Modelling flows of energy and matter through an ecosystem.

Answer 5

• Inputs and outputs (flows) are represented by ARROWS.

- Stock held (storage) is represented by boxes.

Question 6

What are TRANSFERS?

Answer 6

When a flow (of energy/matter) involves a change in location.

Eg. Movements of energy in ocean currents transferring heat, animals eating other animals, water carried by a stream.

Question 7

What are TRANSFORMATIONS?

Answer 7

When a flow (of energy/matter) involves a change of state.

Eg. Matter to energy, energy to matter, energy to energy, matter to matter (chemical or physical changes).

Question 8

Stores and flows in the Carbon Cycle

Answer 8

Stores: Plants, animals, organic matter, atmosphere. They store carbon as matter, but energy is also stored within the carbon bonds of organisms’ chemicals. These bonds flow through the ecosystem as chemical energy.

Flow of matter: transfer of CO2.
Flow of energy: carbon bonds flow as chemical energy.

Storage of CO2 matter: living things that are carbon-based life forms.

Storage of CO2 energy: stored within the carbon bonds of chemicals within organisms.

Stores: atmosphere, plants, animals, fossil fuels, soil.

Flows: photosynthesis, combustion, extraction, respiration, decay, sedimentation.

Question 9

Is the Carbon Cycle a CLOSED or OPEN system?

Answer 9

It is a closed system because it has no inputs or outputs of matter. Its only input is solar energy, and its output is the heat that escapes

Question 10

What are the characteristics of MATTER?

Answer 10

• It cycles endlessly (transfers and comes back).
• It is finite but it is used and reused.
• Eg. There is a fixed mount of carbon in the planet but proportions in stores fluctuate.

Question 11

What are the characteristics of ENERGY?

Answer 11

• Energy flows and is lost (does not go back).
• The ultimate source of energy is the Sun.
• Once heat is lost, it cannot be reused.