Life and Living
What you must understand
Candidates must know the characteristics of living things, the structure and function of plant and animal cells, and how cells, tissues, organs and systems are organised. Understand photosynthesis and respiration as complementary processes, with word equations. Know the parts of a flowering plant and their roles, the process of pollination, fertilisation, seed dispersal and germination. Understand food chains and webs, producers, consumers and decomposers, and how energy flows while nutrients are recycled. Know the main human body systems at a simple level, especially digestion, breathing and circulation, and the importance of a balanced diet, hygiene and disease prevention.
Traps that appear in questions
- Saying plants respire only at night; plants respire all the time and photosynthesise only in light.
- Writing that plants take food from the soil; they make glucose by photosynthesis and absorb water and minerals.
- Confusing pollination (transfer of pollen) with fertilisation (fusion of gametes).
- Drawing energy arrows backwards; arrows show the direction of energy flow, from eaten to eater.
- Claiming energy is recycled in a food chain; nutrients are recycled, energy is lost as heat.
- Forgetting that cell walls are in plant cells but not animal cells.
Rule of thumb and worked example
For any food chain, start with a green plant and point each arrow towards the consumer.
Example: grass → grasshopper → lizard → hawk. The grass is the producer; the grasshopper is a primary consumer; the hawk is a tertiary consumer. If the lizards were removed, grasshoppers would increase and grass would be eaten down, showing that organisms in a chain depend on one another.