6-Waste From Plants & Animals

Question 0

What happens when an organism dies or excretes waste?

Answer 0

The materials are returned to the environment.

Question 1

Why do living things remove materials from the environment?

Answer 1

For growth and other processes.

Question 2

How are materials of a dead animal/its waste returned to the environment?

Answer 2

Microorganisms break down waste and dead bodies. The decay process releases substances used by plants for growth.

Question 3

What is the cycle of recycling the materials of life?

Answer 3

Organism dies/excretes waste.
Broken down by microorganisms.
Absorbed into the ground and used by plants to grow.
Organism eats plants. 
(Repeat)

Question 5

In what conditions do microorganisms digest best?

Answer 5

Warm, moist conditions where there’s plenty of oxygen.

Question 6

What happens in a stable community?

Answer 6

The processes that remove materials are balanced by processes that return materials.

Question 7

What is the definition of the carbon cycle?

Answer 7

The constant recycling of carbon.

Question 8

What is the carbon cycle?

Answer 8

1. CO2 removed from atmosphere by green plants & algae for use in photosynthesis. Some returned through respiration.
2. Carbon obtained by photosynthesis used to make carbohydrates, fats & proteins. When plants eaten by animals the carbon becomes carbohydrates, fats & proteins in animals.
3. Animals respire, releasing CO2.
4. Plants & animals die, other animals and microorganisms feed on their bodies, breaking them down.
5. As detritus feeders and microorganisms eat dead plants & animals, they respire releasing CO2 into the atmosphere.

Question 9

What do the microorganisms and detritus feeders do?

Answer 9

Break down the waste products and dead bodies of organisms and cycle the materials as plant nutrients.

Question 10

What has happened when the microorganisms and detritus feeders have done their job?

Answer 10

All the energy originally captures by green plants has been transferred.

Question 11

What else releases CO2 into the atmosphere?

Answer 11

Combustion of wood and fossil fuels.

Question 12

What are the pros of composting?

Answer 12

• Less methane produced, reduces global warming
• Doesn’t take up space in landfill sites
• Provides plants with nutrients
• Cuts down in buying peat-based composts
• Most councils offer garden-waste collection
• Councils can produce biogas and fertilisers from the waste

Question 13

What are the cons of composting?

Answer 13

• Many food waste items cannot be composted
• Food waste left lying around attracts vermin
• Fewer than 1/2 of councils offer food-waste recycling schemes