Secondary 1 Geography Physical Geography Quiz

Secondary 1 Geography Quiz - Physical Geography

Answer Key

Section A: Multiple Choice

1. D — Crust [1]
The crust is the thinnest outermost layer of the Earth where all life exists. The inner core, outer core, and mantle are all beneath the crust.

2. C — Water cycle [1]
The water cycle (hydrological cycle) describes the continuous movement of water through evaporation, condensation, precipitation, and collection between the atmosphere, land, and oceans.

3. C — Groundwater [1]
Groundwater is a store (where water is held). Evaporation, condensation, and precipitation are processes/flows, not stores.

4. D — Divergent boundary [1]
At a divergent boundary, two tectonic plates move apart from each other. At convergent boundaries plates collide, and at transform boundaries plates slide past each other.

5. C — Biological weathering [1]
Biological weathering involves the breakdown of rocks by living organisms such as plant roots growing into cracks or burrowing animals. Physical weathering involves temperature changes or freeze-thaw; chemical weathering involves reactions like acid rain.

Section B: Short Answer

6. The lithosphere is the rigid outermost layer of the Earth, consisting of the crust and the uppermost part of the mantle. [2]
Marking: 1 mark for identifying it as the rigid outer layer; 1 mark for mentioning it includes the crust and/or upper mantle.

7. [2] — 1 mark each for any TWO valid differences:

(a) Continental crust is thicker (30–70 km) than oceanic crust (5–10 km).
(b) Continental crust is less dense / composed mainly of granite, while oceanic crust is denser / composed mainly of basalt.
(c) Continental crust is older in age compared to oceanic crust.
Accept any two valid differences.

8. (a) Mantle [1]
(b) The inner core is solid / made mainly of iron and nickel / has extremely high temperatures (up to ~5,500°C). [1]
Accept any one valid characteristic.

9. [3]
At a convergent boundary where an oceanic plate meets a continental plate, the denser oceanic plate is forced beneath (subducted under) the less dense continental plate. [1] This creates a deep ocean trench at the boundary. [1] The subducting plate melts as it goes deeper into the mantle, and the magma rises to form volcanic arcs or volcanic mountains on the continental plate. [1]
Marking: 1 mark for subduction, 1 mark for trench, 1 mark for volcanic activity/mountains. Award a max of 2 marks if the explanation lacks detail.

10. [2] — 1 mark each for any TWO valid reasons:

(a) High temperatures and abundant rainfall throughout the year support plant growth.
(b) Multiple layers of vegetation (canopy, understorey, forest floor) provide diverse habitats.
(c) Consistent climate allows species to thrive year-round without seasonal extremes.
(d) High humidity and sunlight support a wide variety of plant and animal species.
Accept any two valid reasons.

Section C: Structured / Data Response

11. [2]
Deforestation removes trees, which reduces transpiration (the release of water vapour from leaves into the atmosphere). [1] This decreases local humidity and can reduce rainfall in the area. [1] Additionally, without tree roots to absorb water, surface runoff increases, which can lead to soil erosion and flooding. [1]
Award 2 marks for a well-explained answer covering at least two points. Award 1 mark for a partial answer.

12. [2]
Weathering is the breakdown of rocks in situ (in place) by physical, chemical, or biological means. [1] Erosion is the wearing away and removal/transport of rock fragments by agents such as water, wind, ice, or gravity. [1]
Key distinction: weathering breaks rocks down; erosion moves the broken material away.

13. Transform boundary [1]
At a transform boundary, two plates slide past each other horizontally. This movement builds up stress that is released as earthquakes (e.g., the San Andreas Fault).

14. (a) November [1]
(b) Working: 280 + 240 + 260 + 290 + 310 + 270 + 250 + 260 + 280 + 320 + 340 + 300 = 3,400 mm [2]
Marking: 1 mark for correct working (showing addition of all 12 months); 1 mark for correct final answer. If working is wrong but answer is correct due to a different method, award 1 mark only.

(c) The rainfall is high throughout the year (above 240 mm every month), which is typical of a tropical climate. [1] Rainfall is highest in the later months of the year (October–November, with November being the wettest at 340 mm), suggesting a wet season towards the end of the year. [1]
Marking: 1 mark for describing consistently high rainfall; 1 mark for identifying the wetter period/pattern.

15. (a) [2] — 1 mark each for any TWO valid characteristics:

(i) Trees have prop/stilt roots that extend into the muddy water.
(ii) Found in coastal/estuarine environments with brackish (mix of salt and fresh) water.
(iii) Dense root systems trap sediment and mud.
(iv) Able to tolerate high salinity levels.
Accept any two valid characteristics.

(b) [2]
The dense network of mangrove roots traps and stabilises sediment, reducing coastal erosion. [1] The roots and trunks act as a natural barrier that absorbs the energy of waves and storm surges, protecting the coastline and inland areas from flooding. [1]
Marking: 1 mark for sediment stabilisation; 1 mark for wave energy absorption/coastal protection.

Section D: Extended Response

16. (a) Evaporation [1]
(b) Precipitation [1]
Common mistake: Students may confuse condensation (water vapour turning into liquid droplets in clouds) with precipitation (water falling from clouds). Ensure the distinction is clear.

17. [3]
Positive effect: Dams store large volumes of water in reservoirs, providing a reliable supply of water for drinking, irrigation, and industrial use. They can also generate hydroelectric power, which is a renewable energy source. [1–2 marks depending on detail]

Negative effect: Dams disrupt the natural flow of rivers, which can reduce the amount of sediment deposited downstream, leading to loss of fertile soil and erosion of river deltas. They can also displace communities and destroy natural habitats upstream when the reservoir floods the area. [1–2 marks depending on detail]

Marking: Award up to 2 marks for a well-explained positive effect and up to 2 marks for a well-explained negative effect. Maximum 3 marks total. At least one positive and one negative point must be made to achieve full marks.

18. [3]
Water enters cracks in the rock during the day. [1] At night, temperatures drop below freezing, causing the water in the cracks to freeze and expand. [1] This expansion puts pressure on the rock, widening the cracks. Over repeated cycles of freezing and thawing, the rock eventually breaks apart. [1]
Marking: 1 mark for water entering cracks; 1 mark for freezing and expanding; 1 mark for repeated cycles causing the rock to break apart.

19. [3]
The greenhouse effect is the natural process where certain gases (greenhouse gases like carbon dioxide and methane) in the Earth's atmosphere trap heat from the sun. [1] Human activities, such as burning fossil fuels and deforestation, have increased the concentration of these greenhouse gases in the atmosphere. [1] This enhanced greenhouse effect traps more heat, causing global temperatures to rise, which is known as global warming. [1]
Marking: 1 mark for explaining the natural greenhouse effect; 1 mark for identifying human activities increasing gas concentrations; 1 mark for linking the enhanced effect to global warming.

20. [4]
At a divergent plate boundary, two tectonic plates move apart from each other. [1] Magma rises from the mantle to fill the gap created by the separating plates. [1] As the magma reaches the surface, it cools and solidifies to form new crust, often creating a mid-ocean ridge (e.g., the Mid-Atlantic Ridge). [1] Over time, repeated volcanic activity builds up the ridge, forming underwater mountains and occasionally volcanic islands (like Iceland) where the magma erupts above sea level. [1]
Marking: 1 mark for plates moving apart; 1 mark for magma rising; 1 mark for forming new crust/ridge; 1 mark for reference to a specific landform (mid-ocean ridge or volcanic island).