← Combined Science syllabus

WalesCombined Science

Unit 1 Biology 1: Plants and ecosystems

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does energy flow through a food chain, and why are food chains short?

Food chains, food webs and trophic levels, pyramids of biomass, and the transfer and loss of energy and biomass between trophic levels.
A focused answer to the WJEC GCSE Science Double Award Unit 1 topic on ecosystems, covering food chains, food webs and trophic levels, pyramids of biomass, and why energy and biomass are lost between trophic levels.
9 min answer →

How is a leaf adapted for photosynthesis, and how do xylem and phloem transport substances in a plant?

The structure of a leaf and how it is adapted for photosynthesis and gas exchange, and the transport of water and food in the xylem and phloem.
A focused answer to the WJEC GCSE Science Double Award Unit 1 topic on leaves and plant transport, covering how the leaf is adapted for photosynthesis and gas exchange, and the roles of the xylem and phloem in transporting water and dissolved food.
9 min answer →

How do plants make food by photosynthesis, and what limits the rate of the reaction?

Photosynthesis as the process that makes glucose using light, the word and symbol equations, the factors that limit the rate of photosynthesis, and the related required practical.
A focused answer to the WJEC GCSE Science Double Award Unit 1 topic on photosynthesis, covering the process and equations, the three limiting factors of light, carbon dioxide and temperature, and the practical investigating the rate of photosynthesis.
10 min answer →

How are carbon and nitrogen recycled through ecosystems, and what role do microorganisms play?

The carbon cycle and the nitrogen cycle, the role of decomposers and named bacteria, and how human activity affects these cycles and biodiversity.
A focused answer to the WJEC GCSE Science Double Award Unit 1 topic on nutrient cycles, covering the carbon cycle, the nitrogen cycle and the bacteria involved, the role of decomposers, and how human activity affects the cycles and biodiversity.
9 min answer →

What is transpiration, and which factors change the rate at which a plant loses water?

Transpiration as the loss of water vapour from a plant, the transpiration stream, and the factors affecting the rate of transpiration.
A focused answer to the WJEC GCSE Science Double Award Unit 1 topic on transpiration, covering transpiration as water loss from the leaves, the transpiration stream up the xylem, and how light, temperature, humidity and wind affect the rate.
9 min answer →