34 UG008982 � Specification � Edexcel GCSE in Science: Single, Double, Separate Sciences B �

recall that plant and animal cells are similar because they contain nuclei, cytoplasm and membranes (7.01)

recall that plant cells also have cellulose cell walls, chloroplasts containing chlorophyll and vacuoles (7.02)

recall the reactants for (carbon dioxide, water) and products of (glucose, oxygen) photosynthesis (7.03)

outline the uses of glucose produced by photosynthesis (respiration, food storage, cellulose and growth) (7.04)

understand that phloem is a living tissue that transports sugars, made during photosynthesis, from the leaves to the fruits and other storage organs (7.05)

explain the interdependence of plants and animals in relation to oxygen and carbon dioxide (7.06)

explain the effect of limiting factors on the rate of photosynthesis, to include light intensity, temperature, carbon dioxide concentration (7.07)

understand why plants need mineral salts (including nitrates to make proteins for growth and magnesium to make chlorophyll) (7.08)

describe how mineral salts are taken up in the roots by active transport using energy from respiration (7.09)

recall that osmosis is the diffusion of water molecules from a region of higher water concentration to a region of lower water concentration through a selectively permeable membrane (7.10)

describe how water is absorbed by the root hairs from the soil by the process of osmosis (7.11)

recall that xylem contains dead hollow cells that transport water from the roots to all other parts of the plant (7.12)

describe how water is lost by diffusion through the stomata of the leaves during transpiration (7.13)

understand the functions of water in plant cells including photosynthesis and maintenance of turgidity (7.14)

describe how the rate of water loss through the stomata varies with temperature, light, air movement, humidity (7.15)

interpret data on how plant hormones affect the growth of roots and shoots (7.16)

describe the commercial use of plant hormones for tissue culture, cuttings, fruit development and killing weeds (7.17)

describe food chains quantitatively using pyramids of biomass (7.18)

describe how energy is transferred in ecosystems through food chains from producers to each level of consumer (7.19)

explain how energy is lost from food chains by respiration and excretion (7.20)

understand that there is a greater loss of energy when the transfer involves a mammal in which energy from respiration is used to generate heat (7.21)

describe how the process of decay is affected by:

describe the carbon cycle including the role of microorganisms, photosynthesis, respiration

describe the reasons for deforestation (including the use of trees as fuel, urban development

understand that sustainable forestry requires replacement planting (7.25)

explain how deforestation has affected the carbon dioxide concentration in the atmosphere

explain how better conservation can lead to greater biodiversity (7.27)

・describe the nitrogen cycle and explain the roles of

� nitrogen-fixing bacteria

� decomposers

� nitrifying bacteria

� denitrifying bacteria

� nitrate fertilisers (7.28)

Maximum Food Production

explain the benefits to farmers of using pesticides, including insecticides, herbicides and

recall the dangers of the over-use of pesticides (7.30)

explain the use of biological control in food production (including the introduction of

explain how greenhouse management maximises food production by optimising conditions for photosynthesis and by controlling pests (7.32)

interpret evidence about the costs and benefits of intensive farming to include the supply of heat, the use of pesticides, inorganic fertilisers and transport (7.33)

recall that biodiversity is the number of different types of living things in an ecosystem (7.34)

evaluate qualitative comparisons of biodiversity between two habitats (7.35)

explain the distribution and relative abundance of common plants growing in an area (7.36)