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Structure and functions in living organisms

Nutrition

2.18-2.20 - Photosynthesis reactions and limiting factorsPhotosynthesis is the process that lets flowering plants trap light energy and store it as chemical energy in glucose. In this lesson, the process is treated as an energy conversion, a pair of equations, and a set of rate patterns. The key exam skill is to connect the graph shape to the factor th...
2.21-2.23 - Leaf adaptations, minerals and photosynthesis practicalLeaves are not just flat green surfaces: their layers, air spaces and transport tissues make photosynthesis efficient. Plants also need mineral ions to build the molecules that let them grow. This lesson finishes with the practical logic for showing oxygen production, starch production, and the r...
2.24-2.26 - Balanced diet and energy requirementsA balanced diet is not a diet where every food component is eaten in equal amounts. It is a diet that supplies the right nutrients, in suitable proportions, for the body's needs. Those needs change with the person's activity level, age and pregnancy, so "balanced" always means matched to the indi...
2.27-2.28 - Alimentary canal and peristalsisFood does not just sit inside the body while it is digested. It passes through a muscular tube called the alimentary canal, where different regions carry out different jobs. This lesson follows the route food takes and then explains the muscle action that keeps it moving.
2.29-2.32 - Digestive enzymes, bile and absorptionFood is useful to the body only after large, insoluble molecules have been digested into small, soluble molecules. Digestive enzymes do the chemical breakdown, bile makes lipid digestion more efficient, and the small intestine absorbs the soluble products into transport systems. This lesson follo...
2.33B - Food energy practicalFood contains chemical energy. In this practical, you estimate how much energy a food sample releases by burning it and measuring how much it warms a known mass of water. The method is simple, so the result is an estimate rather than the true food-label value, but it is excellent for learning fai...

Gas exchange

Transport

Excretion

Co-ordination and response

Reproduction and inheritance

Reproduction

Inheritance

Ecology and the environment

The organism in the environment

Feeding relationships

Cycles within ecosystems

Human influences on the environment

Use of biological resources

Food production

Selective breeding

Genetic modification (genetic engineering)

Cloning