Environment (Environmental Studies)
Science in everyday life
- Plants: roots absorb water and minerals, stems transport them, leaves make food by photosynthesis using light, water and carbon dioxide. Seeds germinate given water, air and suitable warmth - light is needed for healthy growth, not for germination itself.
- Animals: vertebrates have backbones (fish, amphibians, reptiles, birds, mammals). A food chain begins with a green plant, and the arrows show the direction energy travels.
- Matter and water: solids, liquids and gases; the water cycle runs evaporation → condensation → precipitation → collection.
- Energy: metals and graphite conduct electricity while rubber, plastic and dry wood insulate; like magnetic poles repel; a simple circuit needs a source, wires and a component.
Health, safety and citizenship
- A balanced diet supplies carbohydrates, proteins, fats, vitamins, minerals and water.
- Dengue prevention means emptying any container that collects stagnant water.
- First aid: cool a burn under running water; do not burst blisters.
- Sri Lanka has 9 provinces and 25 districts; the Mahaweli is the longest river and Pidurutalagala the highest peak; Sigiriya, Anuradhapura, Polonnaruwa, Kandy, Galle Fort and Sinharaja are UNESCO World Heritage sites.
- National symbols, the three powers of government and citizens' duties are regularly tested.
Worked example
A potted plant is kept in a dark cupboard for two weeks. Predict what happens and why.
Reasoning: without light, photosynthesis slows and chlorophyll fades, so the leaves turn yellow and growth stops. The plant still respires and uses up stored food, so it weakens - it does not "stop breathing" in the dark.
Traps that cost marks
- Claiming plants respire only at night; they respire all the time.
- Swapping the number of provinces (9) and districts (25).
- Choosing an insulator as a conductor, or the reverse.
- Jumbling the order of the water cycle or naming condensation as rainfall.