Test 2

Question 1

What is decomposition?

Answer 1

The breakdown of organic matter (dead plants and animals)

Decomposition is essential for nutrient cycling in ecosystems.

Question 2

What is compost?

Answer 2

Organic matter (e.g. food waste) that has been decomposed

Compost is used as a natural fertilizer for crops and garden plants.

Question 3

What do farmers and gardeners aim for in composting?

Answer 3

Provide ideal conditions for quick decay

Quick decay helps produce compost more efficiently.

Question 4

What microorganisms are primarily involved in decay?

Answer 4

Bacteria and fungi

These microorganisms play a crucial role in breaking down dead organic matter.

Question 5

What factors affect the rate of decay?

Answer 5

Temperature, oxygen availability, water availability, number of decay organisms

Each of these factors influences how quickly microorganisms can break down organic material.

Question 6

How does temperature affect decay?

Answer 6

Higher temperatures increase decay speed; very hot or very cold temperatures slow it down

Enzymes involved in decay work faster at higher temperatures, but extreme heat can destroy them.

Question 7

What is anaerobic decay?

Answer 7

Decay that occurs without oxygen

Anaerobic microorganisms can break down waste materials in environments lacking oxygen.

Question 8

What gas is primarily produced by anaerobic decay?

Answer 8

Methane gas

Methane is a potent greenhouse gas and can be used as a fuel.

Question 9

What is biogas mainly composed of?

Answer 9

Methane

Biogas can be burned as a fuel and is produced in large tanks called generators.

Question 10

What happens inside biogas generators?

Answer 10

Microorganisms break down waste (e.g. sludge waste from sewage works)

This process helps convert waste into usable energy.

Question 11

Fill in the blank: The more microorganisms there are, the ________ decay happens.

Answer 11

faster

A higher number of decay organisms contributes to a quicker breakdown of organic matter.