Earth Cycles Revision

Question 1

What is photosynthesis?

Answer 1

The process used by plants to convert energy from the sun into chemical energy.

Question 2

What is the role of decomposers?

Answer 2

To break down the remains of dead organisms on and below the Earth’s surface.

Question 3

What is the Lithosphere?

Answer 3

The layer includes the crust, upper mantle, and uppermost layers of the earth. Includes two parts; oceanic and continental both of which are broken down into 15 tectonic plates.

Question 4

What are the two most abundant gases in the Earth’s atmosphere?

Answer 4

Oxygen and nitrogen.

Question 5

What are the main greenhouse gases?

Answer 5

Methane, Carbon Dioxide, Nitrous Oxide, and Water Vapour

Question 6

What would be the effect of removing all the carbon dioxide gas from the atmosphere?

Answer 6

Life on Earth would be destroyed as carbon dioxide is necessary for photosynthesis and to trap heat.

Question 7

What is the role of nitrogen-fixing bacteria in the nitrogen cycle?

Answer 7

Transform nitrogen gas from the atmosphere into ‘fixed nitrogen’ compounds such as ammonia and ammonium, usable by plants.

Question 8

What is the role of nitrifying bacteria in the nitrogen cycle?

Answer 8

Responsible for converting soil ammonia into nitrites, then into nitrates through nitrification, meaning plants can absorb and use it.

Question 9

What is the role of denitrifying bacteria in the nitrogen cycle?

Answer 9

Converts nitrates back into nitrogen gas releasing it back into the atmosphere, helping to maintain a balance of nitrogen in the atmosphere and soil.

Question 10

What is the natural greenhouse effect?

Answer 10

A process that warms the Earth’s surface, occurs when the sun’s energy reaches the Earth, where some if it is absorbed and warms the planet. Greenhouse gases trap heat in the atmosphere maintaining a temperature that supports life on Earth.

Question 11

What is the enhanced greenhouse effect?

Answer 11

Human activities add extra greenhouse gases to our atmosphere. These gases trap too much of the sun’s energy, causing global warming. This disrupts weather patterns and contributes to climate change.

Question 12

Explain the importance of greenhouse gases in the atmosphere

Answer 12

Absorbs the sun’s heat that radiates from the Earth’s surface, traps It in the atmosphere and prevents it from escaping into space.

Question 13

3 ways in which human activity has led to an increase in the greenhouse effect.

Answer 13

Burning fossil fuels, cutting down trees, and farming livestock.

Question 14

How has burning fossil fuels contributed to the greenhouse effect?

Answer 14

Produces carbon dioxide and nitrous oxide which are powerful greenhouse gases, that blanket the Earth and trap the sun’s heat.

Question 15

How has cutting down forests contributed to the greenhouse effect?

Answer 15

More carbon is released and less is absorbed, leading to further imbalances in the carbon cycle.

Question 16

How has farming livestock contributed to the greenhouse effect?

Answer 16

Some livestock have microbes called methanogens that produce methane, which is emitted.

Question 17

Suggest two things individuals can do to help reduce our environmental and carbon footprint.

Answer 17

Use more renewable energy - solar, wind
Use energy-efficient appliances at home - LED lighting

Question 18

Why the natural greenhouse effect is vital for life to exist on Earth?

Answer 18

Helps maintain a stable and warm climate, Without it, Earth would be too cold to support liquid water. Greenhouse gases in the atmosphere trap heat from the sun, keeping average temperatures at a level that encourages life.

Question 19

Explain the term greenhouse effect and how it differs from the greenhouse effect.

Answer 19

The intensification of Earth’s natural greenhouse effect due to human activity causes more heat to be trapped leading to global temperatures to rise. The natural greenhouse effect is necessary for life while the enhanced greenhouse effect is driven by human activity and leads to harmful environmental changes.

Question 20

How does climate change impact sea levels?

Answer 20

This leads to thermal expansion which is when ocean water warms and expands due to even small temperature increases. This can lead to a significant rise in sea levels.

Question 21

How does climate change impact the spread of disease/health issues?

Answer 21

Higher temperatures create favourable conditions for disease-carrying insects such as mosquitoes and ticks. Malaria, Lyme and dengue fever may spread to new areas than before putting more populations at risk.

Question 22

How does climate change impact agriculture?

Answer 22

Increases pests and disease leading to crop damage and increased reliance on pesticides.
Affects water availability as changes in precipitation patterns may lead to more frequent droughts.