Olibits / Science / Photosynthesis & Respiration
Primary 6 Science: Photosynthesis & Respiration Practice
Real Primary 6 Science questions on Photosynthesis & Respiration, pulled directly from the Olibits question bank — the same questions a child would actually see, not separately written for this page.
Curriculum alignment
Science Teaching & Learning Syllabus, Primary Three to Six (MOE, 2023 syllabus)
Science is not a taught subject at P1/P2 under MOE's own syllabus — our P1/P2 Science content is offered as enrichment beyond the official syllabus, not as a claim of syllabus coverage at those grades.
Olibits is an independent learning platform and is not affiliated with or endorsed by the Ministry of Education. See our FAQ for the full breakdown.
Real Photosynthesis & Respiration practice questions
A student lists four things she thinks a potted plant needs in order to photosynthesise well: sunlight, water absorbed by the roots, carbon dioxide from the air, and earthworms living in the soil. Which of these is NOT actually needed for photosynthesis to occur?
Sunlight
Earthworms living in the soil ✓
Water absorbed by the roots
Carbon dioxide from the air
Photosynthesis requires light energy, water and carbon dioxide as raw materials/conditions; earthworms in the soil play no direct role in the process itself.
During photosynthesis, plants use carbon dioxide and water with light energy to produce sugar and which other substance?
Water
Carbon dioxide
Oxygen ✓
Minerals from the soil
Photosynthesis combines carbon dioxide and water, using light energy, to produce sugar and release oxygen as a by-product.
What is the main source of energy that powers photosynthesis in most plants?
Light energy, usually from sunlight ✓
Heat energy from the surrounding soil
Chemical energy released by the plant's own respiration
Energy absorbed directly from carbon dioxide in the air
Photosynthesis is powered by light energy, usually from sunlight, which chlorophyll in the leaves absorbs and converts into chemical energy stored in glucose.
A potted plant is placed in a completely dark cupboard for two weeks. What is most likely to happen to it?
There will be no change at all, since plants do not need light
The leaves will grow larger and greener without competing for light
The leaves will turn bright red due to a lack of chlorophyll
The leaves are likely to turn pale or yellow, as the plant cannot photosynthesise without light ✓
Without light, the plant cannot photosynthesise and make food, and chlorophyll production is also affected, so the leaves usually turn pale or yellow and the plant weakens.