The Earth and Space

Question 1

What is the carbon cycle?

Answer 1

The movement of carbon through the biosphere, atmosphere, hydrosphere, and lithosphere via processes like respiration, combustion, and photosynthesis.

Question 2

What role does photosynthesis play in the carbon cycle?

Answer 2

It takes CO₂ from the atmosphere and converts it into glucose in plants.

Question 3

How does respiration contribute to the carbon cycle?

Answer 3

Organisms release CO₂ back into the atmosphere when they break down glucose for energy.

Question 4

How does permafrost affect the carbon cycle?

Answer 4

Melting permafrost releases CO₂ and CH₄ (methane), intensifying the greenhouse effect.

Question 5

Which of the following releases carbon into the atmosphere?
A) Photosynthesis
B) Volcanic eruptions
C) Tree planting
D) Ocean absorption

Answer 5

B. Volcanic eruptions

Question 6

Practice Q: Which activity increases CO₂ in the atmosphere more?
A) Tree planting
B) Deforestation

Answer 6

B. Deforestation – it removes CO₂ absorbing trees and often involves burning.

Question 7

What is permafrost?

Answer 7

Soil that remains frozen for 2+ years, found in polar/high-altitude regions.

Question 8

What is the ‘active layer’ of permafrost?

Answer 8

The upper part that thaws in summer and refreezes in winter.

Question 9

What happens when permafrost melts?

Answer 9

• Methane/CO₂ released → more greenhouse effect
• Soil shifts → unstable buildings/infrastructure
• More erosion and landslides
• Increased plant growth (primary productivity)

Question 10

Practice Q: How does melting permafrost lead to more global warming?

Answer 10

Releases CH₄ (methane), a strong greenhouse gas, which traps heat.

Question 11

Practice Q: What’s a human consequence of melting permafrost?

Answer 11

Unstable foundations → damaged roads, airports, buildings.

Question 12

What is a catchment area (watershed)?

Answer 12

A region where all water drains into the same body of water.

Question 13

What affects water flow in a catchment area?

Answer 13

• Slope of land
• Soil type
• Vegetation
• Urban development

Question 14

Practice Q: Which activity affects water flow most?
A) Swimming pool
B) Dam construction

Answer 14

B. Dam construction

Question 15

Practice Q: A car wash is upstream of a water plant. Should it be fined for dumping waste? Why?

Answer 15

Yes — waste flows downstream and contaminates the water supply.

Question 16

What is salinity?

Answer 16

The concentration of salt in water.

Question 17

What increases salinity?

Answer 17

• Evaporation
• Freezing water (ice leaves salt behind)
• Erosion

Question 18

What decreases salinity?

Answer 18

• Melting glaciers/ice
• Rainfall
• River inflow

Question 19

Practice Q: Which sample has the highest salinity?
A) 4.2g in 115mL
B) 8.32g in 240mL
C) 7.65g in 225mL

Answer 19

A. 4.2g/115mL = 36.5 g/L

Question 20

What effect does low salinity have on density?

Answer 20

Lower salinity → lower density

Question 21

What causes surface currents?

Answer 21

Mainly wind and Earth’s rotation.

Question 22

What causes deep ocean currents?

Answer 22

Differences in density (temperature and salinity).

Question 23

What is thermohaline circulation?

Answer 23

A global conveyor belt moving warm and cold water due to density differences.

Question 24

Practice Q: Which ocean water sinks?
A) Cold + salty
B) Warm + fresh

Answer 24

A. Cold + salty

Question 25

Practice Q: Why does Stornoway have milder winters than Hopedale, even at same latitude?

Answer 25

The Gulf Stream brings warm water to Stornoway → warmer air.

Question 26

What’s the difference between glaciers and pack ice?

Answer 26

- Glaciers: form on land from compacted snow - Pack ice: forms on ocean from frozen seawater

Question 27

Which affect sea levels when it melts: Glaciers or pack ice?

Answer 27

Glaciers (pack ice doesn’t — it’s already in the ocean)

Question 28

What happens when glaciers melt?

Answer 28

- Sea levels rise - Thermohaline circulation slows - Flooding in coastal areas

Question 29

What happens when pack ice melts?

Answer 29

- Loss of animal habitat - Lower ocean salinity - Slower thermohaline circulation - **No sea level change**

Question 30

Practice Q: Why doesn’t melting pack ice cause sea level rise?

Answer 30

It’s already in the water — like ice in a glass of water.

Question 31

Practice Q: What happens to ocean salinity when pack ice melts?

Answer 31

Salinity decreases → density drops → circulation slows

Question 32

What is the greenhouse effect?

Answer 32

A natural process where gases trap heat in the atmosphere, keeping Earth warm.

Question 33

What gases cause it?

Answer 33

CO₂, CH₄ (methane), NOx

Question 34

What intensifies the greenhouse effect?

Answer 34

- Burning fossil fuels - Farming (methane from cows) - Deforestation

Question 35

Why is the greenhouse effect essential for life?

Answer 35

It keeps Earth’s temperature stable enough to support life.

Question 36

Practice Q: Which of these is NOT a greenhouse gas? A) CO₂ B) CH₄ C) SO₂ D) NO₂

Answer 36

C. SO₂

Question 37

Practice Q: What’s the impact of more greenhouse gases?

Answer 37

Traps more heat → global warming → climate change

Question 38

Practice Q: How does deforestation affect the greenhouse effect?

Answer 38

Fewer trees = less CO₂ absorbed → more CO₂ in air → stronger greenhouse effect

Question 39

What is a non-renewable resource?

Answer 39

A resource that cannot be replenished within a human lifetime (ex: fossil fuels, uranium).

Question 40

What is a renewable resource?

Answer 40

A resource that naturally replenishes (ex: wind, solar, hydro).

Question 41

Match the resource to its sphere: Fossil fuels = ? Hydro dams = ? Wind turbines = ?

Answer 41

Fossil fuels = Lithosphere Hydro dams = Hydrosphere Wind turbines = Atmosphere

Question 42

Practice Q: Which is a disadvantage of hydroelectric dams?

Answer 42

They flood habitats and displace animals.

Question 43

Practice Q: What’s an advantage of wind power?

Answer 43

It’s renewable and doesn’t emit greenhouse gases.

Question 44

Practice Q: Which energy source is renewable and from the lithosphere?

Answer 44

Geothermal

Question 45

Practice Q: A community is choosing between coal and tidal power. Which is renewable?

Answer 45

Tidal is renewable; coal is not

Question 46

What is geothermal energy?

Answer 46

Heat energy from inside the Earth, used to generate electricity or heat buildings.

Question 47

Which sphere does geothermal energy come from?

Answer 47

The lithosphere

Question 48

What is tidal energy?

Answer 48

Renewable energy created by ocean tides moving turbines.

Question 49

Which sphere does tidal energy come from?

Answer 49

The hydrosphere

Question 50

What is bioenergy?

Answer 50

Energy from organic material (plants, waste) used as fuel.

Question 51

What is the environmental impact of fossil fuel extraction?

Answer 51

Deforestation, habitat loss, soil erosion, pollution

Question 52

Which renewable resource is linked to the atmosphere?

Answer 52

Wind energy — wind turbines convert atmospheric movement into electricity