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The monocotyledonous plants (Liliidae) and dicotyledonous plants (Magnoliidae) are better known simply as monocots and dicots.

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Mrs Gren is a mnemonic formed from the first letters of the life processes as they are presented here. Mnemonics are useful memory aids.

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Plant and animal cells have many similarities but differ in certain key respects. Animal cells do not have cellulose cell walls, chloroplasts or large, permanent vacuoles.

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Chlorophyll reflects the green component of visible or white light. Most of the energy absorbed is from the blue and red ends of the spectrum.

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Roots anchor plants. Stems hold plants upright, keep leaves and flowers spread out, store starch and provide links between roots and shoots. The leaves of plants are where photosynthesis takes place. Flowers are reproductive structures.

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Photosynthesis is the process by which plants make their own food. Without the energy from food, plants, like all other living organisms, would soon die. Photosynthesis takes place mostly in the leaves of plants, though all green tissues are capable of photosynthesis.

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The rate of photosynthesis is affected by light intensity, temperature, the concentration of carbon dioxide in air and water availability.

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Phloem cells are connected together by perforated end walls or sieve plates. They have no organelles including a nucleus and no vacuoles. Xylem cells are dead. Their cell walls often contain lignin, which provides support.

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Seeds germinate in the dark because they are able to draw on their own stored food reserves. In dicot plants, for example, food is stored in each of the two cotyledons. Fully grown plants need light in order to photosynthesise.

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Herbicides, insectides and fungicides contain chemicals which not only kill off the organisms causing problems but many others too. They are not always selective. Dead or alive, organisms sprayed with pesticides can find their way into and contaminate different trophic levels of food chains. Some organisms eventually become resistant to chemicals.

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Sketches and labelling will vary. Check against text and chapter illustrations. Reproduction takes place in five well-defined stages: pollination, fertilisation, seed formation, seed dispersal and germination.

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Seed germination can be affected by water availability, temperature and oxygen but not usually light. Photosynthesis can be affected by light, temperature, carbon dioxide concentration and water availability.

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Investigations or experiments may vary. If seeds do not usually need light to germinate, for example, this can be tested easily by germinating them in suitable locations (‘Do seeds usually need light to germinate?’). Investigations or experiments with oxygen and carbon dioxide are generally not suitable for the primary classroom.