ZIMSEC · Form 3 · Syllabus 4025
Biology
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- Cell structure and organisation The cell is the basic unit of life. Organisms are made of one cell (unicellular, e.g. Amoeba) or many cells (multicellular).
- Movement in and out of cells Substances move into and out of cells by diffusion, osmosis and active transport.
- Enzymes and biological molecules Food tests: iodine (starch, blue-black), Benedict's (reducing sugar, brick-red on heating), biuret (protein, purple), ethanol emulsion (fat, cloudy white).
- Plant nutrition Plants are autotrophs: they make their own food by photosynthesis.
- Animal nutrition and human digestion Ingestion → digestion → absorption → assimilation → egestion.
- Transport in plants and animals Plants Xylem: dead, hollow, lignified vessels carrying water and minerals up from roots.Phloem: living cells carrying sucrose and…
- Respiration and gas exchange Respiration releases energy from glucose in all living cells. Energy is used for movement, active transport, growth, keeping warm and building molecules.
- Ecology and human impact Producers → primary consumers → secondary consumers → tertiary consumers. Decomposers (bacteria, fungi) break down dead matter and recycle nutrients.