Bio Topics
Bio Topics
3 Subject content
          This syllabus gives you the flexibility to design a course that will interest, challenge and engage your learners.
          Where appropriate you are responsible for selecting resources and examples to support your learners’ study. These
          should be appropriate for the learners’ age, cultural background and learning context as well as complying with
          your school policies and local legal requirements.
          All candidates should be taught the Core subject content. Candidates who are only taught the Core subject content
          can achieve a maximum of grade C. Candidates aiming for grades A* to C should be taught the Extended subject
          content. The Extended subject content includes both the Core and the Supplement.
          Scientific subjects are, by their nature, experimental. Learners should pursue a fully integrated course which allows
          them to develop their experimental skills by doing practical work and investigations across a range of topics.
              Core                                                          Supplement
              1     Describe the characteristics of living organisms
                    by describing:
                    (a)	movement as an action by an organism or
                         part of an organism causing a change of
                         position or place
                    (b)	respiration as the chemical reactions in cells
                         that break down nutrient molecules and
                         release energy for metabolism
                    (c)	sensitivity as the ability to detect and
                         respond to changes in the internal or external
                         environment
                    (d)	growth as a permanent increase in size and
                         dry mass
                    (e)	reproduction as the processes that make
                         more of the same kind of organism
                    (f)	excretion as the removal of the waste
                         products of metabolism and substances in
                         excess of requirements
                    (g)	nutrition as the taking in of materials for
                         energy, growth and development
           Core                                                          Supplement
           1   State that organisms can be classified into groups        5   Explain that classification systems aim to reflect
               by the features that they share                               evolutionary relationships
           2   Describe a species as a group of organisms that
               can reproduce to produce fertile offspring
           3   Describe the binomial system of naming species
               as an internationally agreed system in which the
               scientific name of an organism is made up of two
               parts showing the genus and species
           4   Construct and use dichotomous keys based on
               identifiable features
                                                                         6   Explain that the sequences of bases in DNA are
                                                                             used as a means of classification
                                                                         7   Explain that groups of organisms which share a
                                                                             more recent ancestor (are more closely related)
                                                                             have base sequences in DNA that are more
                                                                             similar than those that share only a distant
                                                                             ancestor
           Core                                                          Supplement
           1	State the main features used to place animals              4	State the main features used to place all
              and plants into the appropriate kingdoms                      organisms into one of the five kingdoms: animal,
                                                                            plant, fungus, prokaryote, protoctist
           2	State the main features used to place organisms            5	State the main features used to place organisms
              into groups within the animal kingdom, limited                into groups within the plant kingdom, limited
              to:                                                           to ferns and flowering plants (dicotyledons and
               (a)	the main groups of vertebrates: mammals,                monocotyledons)
                    birds, reptiles, amphibians, fish
               (b)	the main groups of arthropods: myriapods,
                    insects, arachnids, crustaceans
           3	Classify organisms using the features identified in        6	Classify organisms using the features identified in
              1.3.1 and 1.3.2                                               1.3.4 and 1.3.5
                                                                         7	State the features of viruses, limited to a protein
                                                                            coat and genetic material
           Core                                                            Supplement
           1	Describe and compare the structure of a plant
              cell with an animal cell, limited to: cell wall, cell
              membrane, nucleus, cytoplasm, chloroplasts,
              ribosomes, mitochondria, vacuoles
           2	Describe the structure of a bacterial cell,
              limited to: cell wall, cell membrane, cytoplasm,
              ribosomes, circular DNA, plasmids
           3	Identify the cell structures listed in 2.1.1 and 2.1.2
              in diagrams and images of plant, animal and
              bacterial cells
           4	Describe the functions of the structures listed in
              2.1.1 and 2.1.2 in plant, animal and bacterial cells
           5	State that new cells are produced by division of
              existing cells
           6	State that specialised cells have specific
              functions, limited to:
                (a)	ciliated cells – movement of mucus in the
                     trachea and bronchi
                (b) root hair cells – absorption
                (c) palisade mesophyll cells – photosynthesis
                (d) neurones – conduction of electrical impulses
                (e) red blood cells – transport of oxygen
                (f) sperm and egg cells (gametes) – reproduction
           7	Describe the meaning of the terms: cell, tissue,
              organ, organ system and organism as illustrated
              by examples given in the syllabus
           Core                                                            Supplement
           1    State and use the formula:
                magnification = image size ÷ actual size
           2    Calculate magnification and size of biological             3     Convert measurements between millimetres (mm)
                specimens using millimetres as units                             and micrometres (μm)
           Core                                                            Supplement
           1   Describe diffusion as the net movement
               of particles from a region of their higher
               concentration to a region of their lower
               concentration (i.e. down a concentration
               gradient), as a result of their random movement
           2   State that the energy for diffusion comes from
               the kinetic energy of random movement of
               molecules and ions
           3   State that some substances move into and out of
               cells by diffusion through the cell membrane
           4   Describe the importance of diffusion of gases and
               solutes in living organisms
           5   Investigate the factors that influence diffusion,
               limited to: surface area, temperature,
               concentration gradient and distance
3.2 Osmosis
           Core                                                            Supplement
           1   Describe the role of water as a solvent in                  7   Describe osmosis as the net movement of
               organisms with reference to digestion, excretion                water molecules from a region of higher water
               and transport                                                   potential (dilute solution) to a region of lower
           2   State that water diffuses through partially                     water potential (concentrated solution), through
               permeable membranes by osmosis                                  a partially permeable membrane
           3   State that water moves into and out of cells by
               osmosis through the cell membrane
           4   Investigate osmosis using materials such as
               dialysis tubing
           5   Investigate and describe the effects on plant               8   Explain the effects on plant cells of immersing
               tissues of immersing them in solutions of                       them in solutions of different concentrations
               different concentrations                                        by using the terms: turgid, turgor pressure,
                                                                               plasmolysis, flaccid
                                                                           9   Explain the importance of water potential and
                                                                               osmosis in the uptake and loss of water by
                                                                               organisms
           6   State that plants are supported by the pressure
               of water inside the cells pressing outwards on the
               cell wall
           Core                                                            Supplement
           1    Describe active transport as the movement of               2     Explain the importance of active transport as
                particles through a cell membrane from a region                  a process for movement of molecules or ions
                of lower concentration to a region of higher                     across membranes, including ion uptake by root
                concentration (i.e. against a concentration                      hairs
                gradient), using energy from respiration
                                                                           3     State that protein carriers move molecules or
                                                                                 ions across a membrane during active transport
           4      Biological molecules
           4.1 Biological molecules
           Core                                                            Supplement
           1    List the chemical elements that make up:
                carbohydrates, fats and proteins
           2    State that large molecules are made from smaller
                molecules, limited to:
                (a) starch, glycogen and cellulose from glucose
                (b) proteins from amino acids
                (c) fats and oils from fatty acids and glycerol
           3    Describe the use of:
                (a) iodine solution test for starch
                (b) Benedict’s solution test for reducing sugars
                (c) biuret test for proteins
                (d) ethanol emulsion test for fats and oils
                (e) DCPIP test for vitamin C
                                                                           4     Describe the structure of a DNA molecule:
                                                                                 (a)	two strands coiled together to form a double
                                                                                      helix
                                                                                 (b) each strand contains chemicals called bases
                                                                                 (c)	bonds between pairs of bases hold the
                                                                                      strands together
                                                                                 (d)	the bases always pair up in the same way:
                                                                                      A with T, and C with G (full names are not
                                                                                      required)
           5      Enzymes
           5.1 Enzymes
           Core                                                         Supplement
           1   Describe a catalyst as a substance that increases
               the rate of a chemical reaction and is not
               changed by the reaction
           2   Describe enzymes as proteins that are involved
               in all metabolic reactions, where they function as
               biological catalysts
           3   Describe why enzymes are important in all living
               organisms in terms of a reaction rate necessary
               to sustain life
           4   Describe enzyme action with reference to                 6   Explain enzyme action with reference to: active
               the shape of the active site of an enzyme                    site, enzyme-substrate complex, substrate and
               being complementary to its substrate and the                 product
               formation of products                                    7   Explain the specificity of enzymes in terms of the
                                                                            complementary shape and fit of the active site
                                                                            with the substrate
           5   Investigate and describe the effect of changes           8   Explain the effect of changes in temperature on
               in temperature and pH on enzyme activity                     enzyme activity in terms of kinetic energy, shape
               with reference to optimum temperature and                    and fit, frequency of effective collisions and
               denaturation                                                 denaturation
                                                                        9   Explain the effect of changes in pH on
                                                                            enzyme activity in terms of shape and fit and
                                                                            denaturation
           6      Plant nutrition
           6.1 Photosynthesis
           Core                                                         Supplement
           1   Describe photosynthesis as the process by
               which plants synthesise carbohydrates from raw
               materials using energy from light
           2   State the word equation for photosynthesis as:           10 State the balanced chemical equation for
               carbon dioxide + water → glucose + oxygen                   photosynthesis as:
               in the presence of light and chlorophyll                     6CO2 + 6H2O → C6H12O6 + 6O2
           3   State that chlorophyll is a green pigment that is
               found in chloroplasts
           4   State that chlorophyll transfers energy from light
               into energy in chemicals, for the synthesis of
               carbohydrates
                                                                                                                       continued
           Core                                                            Supplement
           5    Outline the subsequent use and storage of the
                carbohydrates made in photosynthesis, limited
                to:
                (a) starch as an energy store
                (b) cellulose to build cell walls
                (c) glucose used in respiration to provide energy
                (d) sucrose for transport in the phloem
                (e) nectar to attract insects for pollination
           6    Explain the importance of:
                (a) nitrate ions for making amino acids
                (b) magnesium ions for making chlorophyll
           7    Investigate the need for chlorophyll, light
                and carbon dioxide for photosynthesis, using
                appropriate controls
           8    Investigate and describe the effects of varying
                light intensity, carbon dioxide concentration and
                temperature on the rate of photosynthesis
           9    Investigate and describe the effect of light and
                dark conditions on gas exchange in an aquatic
                plant using hydrogencarbonate indicator solution
                                                                           11 Identify and explain the limiting factors of
                                                                              photosynthesis in different environmental
                                                                              conditions
           Core                                                            Supplement
           1    State that most leaves have a large surface area
                and are thin, and explain how these features are
                adaptations for photosynthesis
           2    Identify in diagrams and images the following
                structures in the leaf of a dicotyledonous plant:
                chloroplasts, cuticle, guard cells and stomata,
                upper and lower epidermis, palisade mesophyll,
                spongy mesophyll, air spaces, vascular bundles,
                xylem and phloem
           3    Explain how the structures listed in 6.2.2 adapt
                leaves for photosynthesis
           7      Human nutrition
           7.1 Diet
           Core                                                            Supplement
           1   Describe what is meant by a balanced diet
           2   State the principal dietary sources and describe
               the importance of:
               (a) carbohydrates
               (b) fats and oils
               (c) proteins
               (d) vitamins, limited to C and D
               (e) mineral ions, limited to calcium and iron
               (f) fibre (roughage)
               (g) water
           3   State the causes of scurvy and rickets
           Core                                                            Supplement
           1   Identify in diagrams and images the main organs
               of the digestive system, limited to:
               (a)	alimentary canal: mouth, oesophagus,
                    stomach, small intestine (duodenum and
                    ileum) and large intestine (colon, rectum,
                    anus)
               (b)	associated organs: salivary glands, pancreas,
                    liver and gall bladder
           2   Describe the functions of the organs of the
               digestive system listed in 7.2.1, in relation to:
               (a)	ingestion – the taking of substances, e.g. food
                    and drink, into the body
               (b) digestion – the breakdown of food
               (c)	absorption – the movement of nutrients from
                    the intestines into the blood
               (d)	assimilation – uptake and use of nutrients by
                    cells
               (e)	egestion – the removal of undigested food
                    from the body as faeces
           Core                                                            Supplement
           1    Describe physical digestion as the breakdown of
                food into smaller pieces without chemical change
                to the food molecules
           2    State that physical digestion increases the
                surface area of food for the action of enzymes in
                chemical digestion
           3    Identify in diagrams and images the types of
                human teeth: incisors, canines, premolars and
                molars
           4    Describe the structure of human teeth, limited
                to: enamel, dentine, pulp, nerves, blood vessels
                and cement, and understand that teeth are
                embedded in bone and the gums
           5    Describe the functions of the types of human
                teeth in physical digestion of food
           6    Describe the function of the stomach in physical
                digestion
                                                                           7     Outline the role of bile in emulsifying fats and
                                                                                 oils to increase the surface area for chemical
                                                                                 digestion
           Core                                                            Supplement
           1    Describe chemical digestion as the break down
                of large insoluble molecules into small soluble
                molecules
           2    State the role of chemical digestion in producing
                small soluble molecules that can be absorbed
           3    Describe the functions of enzymes as follows:              6     Describe the digestion of starch in the digestive
                (a)	amylase breaks down starch to simple                        system:
                     reducing sugars                                             (a) amylase breaks down starch to maltose
                (b) proteases break down protein to amino acids                  (b)	maltase breaks down maltose to glucose on
                (c)	lipase breaks down fats and oils to fatty acids                  the membranes of the epithelium lining the
                     and glycerol                                                     small intestine
           4    State where, in the digestive system, amylase,             7     Describe the digestion of protein by proteases in
                protease and lipase are secreted and where they                  the digestive system:
                act                                                              (a)	pepsin breaks down protein in the acidic
           5    Describe the functions of hydrochloric acid                           conditions of the stomach
                in gastric juice, limited to killing harmful                     (b)	trypsin breaks down protein in the alkaline
                microorganisms in food and providing an acidic                        conditions of the small intestine
                pH for optimum enzyme activity
                                                                           8     Explain that bile is an alkaline mixture that
                                                                                 neutralises the acidic mixture of food and gastric
                                                                                 juices entering the duodenum from the stomach,
                                                                                 to provide a suitable pH for enzyme action
7.5 Absorption
           Core                                                          Supplement
           1   State that the small intestine is the region where
               nutrients are absorbed
                                                                         3   Explain the significance of villi and microvilli in
                                                                             increasing the internal surface area of the small
                                                                             intestine
                                                                         4   Describe the structure of a villus
                                                                         5   Describe the roles of capillaries and lacteals in
                                                                             villi
           2   State that most water is absorbed from the small
               intestine but that some is also absorbed from the
               colon
           8      Transport in plants
           8.1 Xylem and phloem
           Core                                                          Supplement
           1   State the functions of xylem and phloem:                  3   Relate the structure of xylem vessels to their
               (a)	xylem – transport of water and mineral ions,             function, limited to:
                    and support                                              (a)	thick walls with lignin (details of lignification
               (b)	phloem – transport of sucrose and amino                       are not required)
                    acids                                                    (b) no cell contents
           2   Identify in diagrams and images the position of               (c)	cells joined end to end with no cross walls to
               xylem and phloem as seen in sections of roots,                     form a long continuous tube
               stems and leaves of non-woody dicotyledonous
               plants
           Core                                                          Supplement
           1   Identify in diagrams and images root hair cells
               and state their functions
           2   State that the large surface area of root hairs
               increases the uptake of water and mineral ions
           3   Outline the pathway taken by water through the
               root, stem and leaf as: root hair cells, root cortex
               cells, xylem, mesophyll cells
           4   Investigate, using a suitable stain, the pathway of
               water through the above-ground parts of a plant
8.3 Transpiration
           Core                                                            Supplement
           1    Describe transpiration as the loss of water vapour
                from leaves
           2    State that water evaporates from the surfaces of
                the mesophyll cells into the air spaces and then
                diffuses out of the leaves through the stomata as
                water vapour
                                                                           4     Explain how water vapour loss is related to:
                                                                                 the large internal surface area provided by the
                                                                                 interconnecting air spaces between mesophyll
                                                                                 cells and the size and number of stomata
                                                                           5     Explain the mechanism by which water moves
                                                                                 upwards in the xylem in terms of a transpiration
                                                                                 pull that draws up a column of water molecules,
                                                                                 held together by forces of attraction between
                                                                                 water molecules
           3    Investigate and describe the effects of variation          6     Explain the effects on the rate of transpiration of
                of temperature and wind speed on transpiration                   varying the following factors: temperature, wind
                rate                                                             speed and humidity
                                                                           7     Explain how and why wilting occurs
8.4 Translocation
           Core                                                            Supplement
                                                                           1     Describe translocation as the movement of
                                                                                 sucrose and amino acids in phloem from sources
                                                                                 to sinks
                                                                           2     Describe:
                                                                                 (a)	sources as the parts of plants that release
                                                                                      sucrose or amino acids
                                                                                 (b)	sinks as the parts of plants that use or store
                                                                                      sucrose or amino acids
                                                                           3     Explain why some parts of a plant may act as a
                                                                                 source and a sink at different times
           9      Transport in animals
           9.1 Circulatory systems
           Core                                                          Supplement
           1   Describe the circulatory system as a system of
               blood vessels with a pump and valves to ensure
               one-way flow of blood
                                                                         2   Describe the single circulation of a fish
                                                                         3   Describe the double circulation of a mammal
                                                                         4   Explain the advantages of a double circulation
9.2 Heart
           Core                                                          Supplement
           1   Identify in diagrams and images the structures of         7   Identify in diagrams and images the
               the mammalian heart, limited to: muscular wall,               atrioventricular and semilunar valves in the
               septum, left and right ventricles, left and right             mammalian heart
               atria, one-way valves and coronary arteries               8   Explain the relative thickness of:
                                                                             (a)	the muscle walls of the left and right
                                                                                  ventricles
                                                                             (b)	the muscle walls of the atria compared to
                                                                                  those of the ventricles
                                                                         9   Explain the importance of the septum in
                                                                             separating oxygenated and deoxygenated blood
                                                                         10 Describe the functioning of the heart in terms
                                                                            of the contraction of muscles of the atria and
                                                                            ventricles and the action of the valves
           2   State that blood is pumped away from the heart
               in arteries and returns to the heart in veins
           3   State that the activity of the heart may be
               monitored by: ECG, pulse rate and listening to
               sounds of valves closing
           4   Investigate and describe the effect of physical           11 Explain the effect of physical activity on the heart
               activity on the heart rate                                   rate
           5   Describe coronary heart disease in terms of
               the blockage of coronary arteries and state
               the possible risk factors including: diet, lack of
               exercise, stress, smoking, genetic predisposition,
               age and sex
           6   Discuss the roles of diet and exercise in reducing
               the risk of coronary heart disease
           Core                                                            Supplement
           1    Describe the structure of arteries, veins and              4     Explain how the structure of arteries and veins
                capillaries, limited to: relative thickness of wall,             is related to the pressure of the blood that they
                diameter of the lumen and the presence of valves                 transport
                in veins
           2    State the functions of capillaries                         5     Explain how the structure of capillaries is related
                                                                                 to their functions
           3    Identify in diagrams and images the main blood             6     Identify, in diagrams and images, the main blood
                vessels to and from the:                                         vessels to and from the liver as: hepatic artery,
                (a)	heart, limited to: vena cava, aorta, pulmonary              hepatic veins and hepatic portal vein
                     artery and pulmonary vein
                (b)	lungs, limited to: pulmonary artery and
                     pulmonary vein
                (c) kidney, limited to: renal artery and renal vein
9.4 Blood
           Core                                                            Supplement
           1    List the components of blood as: red blood cells,
                white blood cells, platelets and plasma
           2    Identify red and white blood cells in                      5     Identify lymphocytes and phagocytes in
                photomicrographs and diagrams                                    photomicrographs and diagrams
           3    State the functions of the following components            6     State the functions of:
                of blood:                                                        (a) lymphocytes – antibody production
                (a)	red blood cells in transporting oxygen,                     (b)	phagocytes – engulfing pathogens by
                     including the role of haemoglobin                                phagocytosis
                (b)	white blood cells in phagocytosis and
                     antibody production
                (c) platelets in clotting (details are not required)
                (d)	plasma in the transport of blood cells, ions,
                     nutrients, urea, hormones and carbon dioxide
           4    State the roles of blood clotting as preventing            7     Describe the process of clotting as the conversion
                blood loss and the entry of pathogens                            of fibrinogen to fibrin to form a mesh
           Core                                                          Supplement
           1   Describe a pathogen as a disease-causing
               organism
           2   Describe a transmissible disease as a disease in
               which the pathogen can be passed from one host
               to another
           3   State that a pathogen is transmitted:
               (a)	by direct contact, including through blood
                    and other body fluids
               (b)	indirectly, including from contaminated
                    surfaces, food, animals and air
           4   Describe the body defences, limited to: skin,             6   Describe active immunity as defence against a
               hairs in the nose, mucus, stomach acid and white              pathogen by antibody production in the body
               blood cells                                               7   State that each pathogen has its own antigens,
           5   Explain the importance of the following in                    which have specific shapes
               controlling the spread of disease:                        8   Describe antibodies as proteins that bind
               (a) a clean water supply                                      to antigens leading to direct destruction
               (b) hygienic food preparation                                 of pathogens or marking of pathogens for
                                                                             destruction by phagocytes
               (c) good personal hygiene
                                                                         9   State that specific antibodies have
               (d) waste disposal
                                                                             complementary shapes which fit specific antigens
               (e)	sewage treatment (details of the stages of
                                                                         10 Explain that active immunity is gained after an
                    sewage treatment are not required)
                                                                            infection by a pathogen or by vaccination
                                                                         11 Outline the process of vaccination:
                                                                             (a)	weakened pathogens or their antigens are
                                                                                  put into the body
                                                                             (b)	the antigens stimulate an immune response
                                                                                  by lymphocytes which produce antibodies
                                                                             (c)	memory cells are produced that give
                                                                                  long-term immunity
                                                                         12 Explain the role of vaccination in controlling the
                                                                            spread of diseases
                                                                         13 Explain that passive immunity is a short-term
                                                                            defence against a pathogen by antibodies
                                                                            acquired from another individual, including
                                                                            across the placenta and in breast milk
                                                                         14 Explain the importance of breast-feeding for the
                                                                            development of passive immunity in infants
                                                                         15 State that memory cells are not produced in
                                                                            passive immunity
                                                                                                                        continued
           Core                                                            Supplement
                                                                           16 Describe cholera as a disease caused by a
                                                                              bacterium which is transmitted in contaminated
                                                                              water
                                                                           17 Explain that the cholera bacterium produces a
                                                                              toxin that causes secretion of chloride ions into
                                                                              the small intestine, causing osmotic movement
                                                                              of water into the gut, causing diarrhoea,
                                                                              dehydration and loss of ions from the blood
           Core                                                            Supplement
           1    Describe the features of gas exchange surfaces
                in humans, limited to: large surface area, thin
                surface, good blood supply and good ventilation
                with air
           2    Identify in diagrams and images the following              6     Identify in diagrams and images the internal and
                parts of the breathing system: lungs, diaphragm,                 external intercostal muscles
                ribs, intercostal muscles, larynx, trachea, bronchi,
                bronchioles, alveoli and associated capillaries
                                                                           7     State the function of cartilage in the trachea
                                                                           8     Explain the role of the ribs, the internal and
                                                                                 external intercostal muscles and the diaphragm
                                                                                 in producing volume and pressure changes in the
                                                                                 thorax leading to the ventilation of the lungs
           3    Investigate the differences in composition                 9     Explain the differences in composition between
                between inspired and expired air using limewater                 inspired and expired air
                as a test for carbon dioxide
           4    Describe the differences in composition between
                inspired and expired air, limited to: oxygen,
                carbon dioxide and water vapour
           5    Investigate and describe the effects of physical           10 Explain the link between physical activity and
                activity on the rate and depth of breathing                   the rate and depth of breathing in terms of: an
                                                                              increased carbon dioxide concentration in the
                                                                              blood, which is detected by the brain, leading to
                                                                              an increased rate and greater depth of breathing
                                                                           11 Explain the role of goblet cells, mucus and
                                                                              ciliated cells in protecting the breathing system
                                                                              from pathogens and particles
           12 Respiration
           12.1 Respiration
           Core                                                         Supplement
           1   State the uses of energy in living organisms,
               including: muscle contraction, protein synthesis,
               cell division, active transport, growth, the
               passage of nerve impulses and the maintenance
               of a constant body temperature
           2   Investigate and describe the effect of
               temperature on respiration in yeast
           Core                                                         Supplement
           1   Describe aerobic respiration as the chemical
               reactions in cells that use oxygen to break down
               nutrient molecules to release energy
           2   State the word equation for aerobic respiration as:      3   State the balanced chemical equation for aerobic
               glucose + oxygen → carbon dioxide + water                    respiration as:
                                                                            C6H12O6 + 6O2 → 6CO2 + 6H2O
           Core                                                         Supplement
           1   Describe anaerobic respiration as the chemical
               reactions in cells that break down nutrient
               molecules to release energy without using
               oxygen
           2   State that anaerobic respiration releases much
               less energy per glucose molecule than aerobic
               respiration
           3   State the word equation for anaerobic respiration        5   State the balanced chemical equation for
               in yeast as:                                                 anaerobic respiration in yeast as:
               glucose → alcohol + carbon dioxide                           C6H12O6 → 2C2H5OH + 2CO2
           4   State the word equation for anaerobic respiration
               in muscles during vigorous exercise as:
               glucose → lactic acid
                                                                        6   State that lactic acid builds up in muscles and
                                                                            blood during vigorous exercise causing an oxygen
                                                                            debt
                                                                                                                       continued
           Core                                                            Supplement
                                                                           7     Outline how the oxygen debt is removed after
                                                                                 exercise, limited to:
                                                                                 (a)	continuation of fast heart rate to transport
                                                                                      lactic acid in the blood from the muscles to
                                                                                      the liver
                                                                                 (b)	continuation of deeper and faster breathing
                                                                                      to supply oxygen for aerobic respiration of
                                                                                      lactic acid
                                                                                 (c) aerobic respiration of lactic acid in the liver
           13 Excretion in humans
           13.1 Excretion in humans
           Core                                                            Supplement
           1    State that carbon dioxide is excreted through the
                lungs
           2    State that the kidneys excrete urea and excess
                water and ions
           3    Identify in diagrams and images the kidneys,               4     Identify in diagrams and images the structure of
                ureters, bladder and urethra                                     the kidney, limited to the cortex and medulla
                                                                           5     Outline the structure and function of a nephron
                                                                                 and its associated blood vessels, limited to:
                                                                                 (a)	the role of the glomerulus in the filtration
                                                                                      from the blood of water, glucose, urea and
                                                                                      ions
                                                                                 (b)	the role of the nephron in the reabsorption of
                                                                                      all of the glucose, some of the ions and most
                                                                                      of the water back into the blood
                                                                                 (c)	the formation of urine containing urea,
                                                                                      excess water and excess ions
                                                                                 (details of these processes are not required)
                                                                           6     Describe the role of the liver in the assimilation
                                                                                 of amino acids by converting them to proteins
                                                                           7     State that urea is formed in the liver from excess
                                                                                 amino acids
                                                                           8     Describe deamination as the removal of the
                                                                                 nitrogen-containing part of amino acids to form
                                                                                 urea
                                                                           9     Explain the importance of excretion, limited to
                                                                                 toxicity of urea
           Core                                                         Supplement
           1   State that electrical impulses travel along
               neurones
           2   Describe the mammalian nervous system in
               terms of:
               (a)	the central nervous system (CNS) consisting
                    of the brain and the spinal cord
               (b)	the peripheral nervous system (PNS)
                    consisting of the nerves outside of the brain
                    and spinal cord
           3   Describe the role of the nervous system as
               coordination and regulation of body functions
           4   Identify in diagrams and images sensory, relay
               and motor neurones
           5   Describe a simple reflex arc in terms of: receptor,
               sensory neurone, relay neurone, motor neurone
               and effector
           6   Describe a reflex action as a means of
               automatically and rapidly integrating and
               coordinating stimuli with the responses of
               effectors (muscles and glands)
           7   Describe a synapse as a junction between two             8   Describe the structure of a synapse, including the
               neurones                                                     presence of vesicles containing neurotransmitter
                                                                            molecules, the synaptic gap and receptor
                                                                            proteins
                                                                        9   Describe the events at a synapse as:
                                                                            (a)	an impulse stimulates the release of
                                                                                 neurotransmitter molecules from vesicles
                                                                                 into the synaptic gap
                                                                            (b)	the neurotransmitter molecules diffuse
                                                                                 across the gap
                                                                            (c)	neurotransmitter molecules bind with
                                                                                 receptor proteins on the next neurone
                                                                            (d)	an impulse is then stimulated in the next
                                                                                 neurone
                                                                        10 State that synapses ensure that impulses travel in
                                                                           one direction only
           Core                                                            Supplement
           1    Describe sense organs as groups of receptor cells
                responding to specific stimuli: light, sound, touch,
                temperature and chemicals
           2    Identify in diagrams and images the structures of
                the eye, limited to: cornea, iris, pupil, lens, retina,
                optic nerve and blind spot
           3    Describe the function of each part of the eye,
                limited to:
                (a) cornea – refracts light
                (b)	iris – controls how much light enters the
                     pupil
                (c) lens – focuses light on to the retina
                (d)	retina – contains light receptors, some
                     sensitive to light of different colours
                (e) optic nerve – carries impulses to the brain
           4    Explain the pupil reflex, limited to changes in            5     Explain the pupil reflex in terms of the
                light intensity and pupil diameter                               antagonistic action of circular and radial muscles
                                                                                 in the iris
                                                                           6     Explain accommodation to view near and distant
                                                                                 objects in terms of the contraction and relaxation
                                                                                 of the ciliary muscles, tension in the suspensory
                                                                                 ligaments, shape of the lens and refraction of
                                                                                 light
                                                                           7     Describe the distribution of rods and cones in the
                                                                                 retina of a human
                                                                           8     Outline the function of rods and cones, limited
                                                                                 to:
                                                                                 (a) greater sensitivity of rods for night vision
                                                                                 (b)	three different kinds of cones, absorbing light
                                                                                      of different colours, for colour vision
                                                                           9     Identify in diagrams and images the position of
                                                                                 the fovea and state its function
14.3 Hormones
           Core                                                            Supplement
           1   Describe a hormone as a chemical substance,
               produced by a gland and carried by the blood,
               which alters the activity of one or more specific
               target organs
           2   Identify in diagrams and images specific                    5   State that glucagon is secreted by the pancreas
               endocrine glands and state the hormones they
               secrete, limited to:
               (a) adrenal glands and adrenaline
               (b) pancreas and insulin
               (c) testes and testosterone
               (d) ovaries and oestrogen
           3   Describe adrenaline as the hormone secreted in              6   Describe the role of adrenaline in the control of
               ‘fight or flight’ situations and its effects, limited           metabolic activity, limited to:
               to:                                                             (a)	increasing the blood glucose concentration
               (a) increased breathing rate                                    (b) increasing heart rate
               (b) increased heart rate
               (c) increased pupil diameter
           4   Compare nervous and hormonal control, limited
               to speed of action and duration of effect
14.4 Homeostasis
           Core                                                            Supplement
           1   Describe homeostasis as the maintenance of a                3   Explain the concept of homeostatic control by
               constant internal environment                                   negative feedback with reference to a set point
           2   State that insulin decreases blood glucose                  4   Describe the control of blood glucose
               concentration                                                   concentration by the liver and the roles of insulin
                                                                               and glucagon
                                                                           5   Outline the treatment of Type 1 diabetes
                                                                           6   Identify in diagrams and images of the skin: hairs,
                                                                               hair erector muscles, sweat glands, receptors,
                                                                               sensory neurones, blood vessels and fatty tissue
                                                                           7   Describe the maintenance of a constant internal
                                                                               body temperature in mammals in terms of:
                                                                               insulation, sweating, shivering and the role of the
                                                                               brain
                                                                           8   Describe the maintenance of a constant internal
                                                                               body temperature in mammals in terms of
                                                                               vasodilation and vasoconstriction of arterioles
                                                                               supplying skin surface capillaries
           Core                                                            Supplement
           1    Describe gravitropism as a response in which               4     Explain phototropism and gravitropism of a shoot
                parts of a plant grow towards or away from                       as examples of the chemical control of plant
                gravity                                                          growth
           2    Describe phototropism as a response in which               5     Explain the role of auxin in controlling shoot
                parts of a plant grow towards or away from the                   growth, limited to:
                direction of the light source                                    (a) auxin is made in the shoot tip
           3    Investigate and describe gravitropism and                        (b)	auxin diffuses through the plant from the
                phototropism in shoots and roots                                      shoot tip
                                                                                 (c)	auxin is unequally distributed in response to
                                                                                      light and gravity
                                                                                 (d) auxin stimulates cell elongation
           15 Drugs
           15.1 Drugs
           Core                                                            Supplement
           1    Describe a drug as any substance taken into the
                body that modifies or affects chemical reactions
                in the body
           2    Describe the use of antibiotics for the treatment
                of bacterial infections
           3    State that some bacteria are resistant to                  5     Explain how using antibiotics only when essential
                antibiotics which reduces the effectiveness of                   can limit the development of resistant bacteria
                antibiotics                                                      such as MRSA
           4    State that antibiotics kill bacteria but do not
                affect viruses
           16 Reproduction
           16.1 Asexual reproduction
           Core                                                            Supplement
           1    Describe asexual reproduction as a process
                resulting in the production of genetically
                identical offspring from one parent
           2    Identify examples of asexual reproduction in
                diagrams, images and information provided
                                                                           3     Discuss the advantages and disadvantages of
                                                                                 asexual reproduction:
                                                                                 (a) to a population of a species in the wild
                                                                                 (b) to crop production
           Core                                                          Supplement
           1   Describe sexual reproduction as a process                 3   State that nuclei of gametes are haploid and that
               involving the fusion of the nuclei of two gametes             the nucleus of a zygote is diploid
               to form a zygote and the production of offspring
               that are genetically different from each other
           2   Describe fertilisation as the fusion of the nuclei of
               gametes
                                                                         4   Discuss the advantages and disadvantages of
                                                                             sexual reproduction:
                                                                             (a) to a population of a species in the wild
                                                                             (b) to crop production
           Core                                                          Supplement
           1   Identify in diagrams and images and draw the
               following parts of an insect-pollinated flower:
               sepals, petals, stamens, filaments, anthers,
               carpels, style, stigma, ovary and ovules
           2   State the functions of the structures listed in
               16.3.1
           3   Identify in diagrams and images and describe the
               anthers and stigmas of a wind-pollinated flower
           4   Distinguish between the pollen grains of
               insect-pollinated and wind-pollinated flowers
           5   Describe pollination as the transfer of pollen
               grains from an anther to a stigma
                                                                         9   Describe self-pollination as the transfer of pollen
                                                                             grains from the anther of a flower to the stigma
                                                                             of the same flower or a different flower on the
                                                                             same plant
                                                                         10 Describe cross-pollination as the transfer of
                                                                            pollen grains from the anther of a flower to the
                                                                            stigma of a flower on a different plant of the
                                                                            same species
                                                                         11 Discuss the potential effects of self-pollination
                                                                            and cross-pollination on a population, in terms of
                                                                            variation, capacity to respond to changes in the
                                                                            environment and reliance on pollinators
                                                                                                                        continued
           Core                                                            Supplement
           6    State that fertilisation occurs when a pollen              12 Describe the growth of the pollen tube and its
                nucleus fuses with a nucleus in an ovule                      entry into the ovule followed by fertilisation
           7    Describe the structural adaptations of                        (details of production of endosperm and
                insect-pollinated and wind-pollinated flowers                 development are not required)
           8    Investigate and describe the environmental
                conditions that affect germination of seeds,
                limited to the requirement for: water, oxygen and
                a suitable temperature
           Core                                                            Supplement
           1    Identify on diagrams and state the functions
                of the following parts of the male reproductive
                system: testes, scrotum, sperm ducts, prostate
                gland, urethra and penis
           2    Identify on diagrams and state the functions of
                the following parts of the female reproductive
                system: ovaries, oviducts, uterus, cervix and
                vagina
           3    Describe fertilisation as the fusion of the nuclei
                from a male gamete (sperm) and a female
                gamete (egg cell)
           4    Explain the adaptive features of sperm, limited
                to: flagellum, mitochondria and enzymes in the
                acrosome
           5    Explain the adaptive features of egg cells, limited
                to: energy stores and the jelly coat that changes
                at fertilisation
           6    Compare male and female gametes in terms of:
                size, structure, motility and numbers
           7    State that in early development, the zygote
                forms an embryo which is a ball of cells that
                implants into the lining of the uterus
           8    Identify on diagrams and state the functions of            9     Describe the function of the placenta and
                the following in the development of the fetus:                   umbilical cord in relation to the exchange of
                umbilical cord, placenta, amniotic sac and                       dissolved nutrients, gases and excretory products
                amniotic fluid                                                   between the blood of the mother and the blood
                                                                                 of the fetus
                                                                           10 State that some pathogens and toxins can pass
                                                                              across the placenta and affect the fetus
           Core                                                         Supplement
           1   Describe the roles of testosterone and oestrogen
               in the development and regulation of secondary
               sexual characteristics during puberty
           2   Describe the menstrual cycle in terms of changes         3   Describe the sites of production of oestrogen
               in the ovaries and in the lining of the uterus               and progesterone in the menstrual cycle and in
                                                                            pregnancy
                                                                        4   Explain the role of hormones in controlling the
                                                                            menstrual cycle and pregnancy, limited to FSH,
                                                                            LH, progesterone and oestrogen
           Core                                                         Supplement
           1   Describe a sexually transmitted infection (STI) as
               an infection that is transmitted through sexual
               contact
           2   State that human immunodeficiency virus (HIV)
               is a pathogen that causes an STI
           3   State that HIV infection may lead to AIDS
           4   Describe the methods of transmission of HIV
           5   Explain how the spread of STIs is controlled
           17 Inheritance
           17.1 Chromosomes, genes and proteins
           Core                                                         Supplement
           1   State that chromosomes are made of DNA,
               which contains genetic information in the form
               of genes
           2   Define a gene as a length of DNA that codes for a
               protein
           3   Define an allele as an alternative form of a gene
           4   Describe the inheritance of sex in humans with
               reference to X and Y chromosomes
                                                                        5   State that the sequence of bases in a gene
                                                                            determines the sequence of amino acids used to
                                                                            make a specific protein (knowledge of the details
                                                                            of nucleotide structure is not required)
                                                                        6   Explain that different sequences of amino acids
                                                                            give different shapes to protein molecules
                                                                                                                       continued
           Core                                                            Supplement
                                                                           7     Explain that DNA controls cell function by
                                                                                 controlling the production of proteins, including
                                                                                 enzymes, membrane carriers and receptors for
                                                                                 neurotransmitters
                                                                           8     Explain how a protein is made, limited to:
                                                                                 •   the gene coding for the protein remains in
                                                                                     the nucleus
                                                                                 •   messenger RNA (mRNA) is a copy of a gene
                                                                                 •   mRNA molecules are made in the nucleus
                                                                                     and move to the cytoplasm
                                                                                 •   the mRNA passes through ribosomes
                                                                                 •   the ribosome assembles amino acids into
                                                                                     protein molecules
                                                                                 •
                                                                                 the specific sequence of amino acids is
                                                                                 determined by the sequence of bases in the
                                                                                 mRNA
                                                                           	(knowledge of the details of transcription or
                                                                             translation is not required)
                                                                           9     Explain that most body cells in an organism
                                                                                 contain the same genes, but many genes in a
                                                                                 particular cell are not expressed because the cell
                                                                                 only makes the specific proteins it needs
                                                                           10 Describe a haploid nucleus as a nucleus
                                                                              containing a single set of chromosomes
                                                                           11 Describe a diploid nucleus as a nucleus containing
                                                                              two sets of chromosomes
                                                                           12 State that in a diploid cell, there is a pair of each
                                                                              type of chromosome and in a human diploid cell
                                                                              there are 23 pairs
17.2 Mitosis
           Core                                                            Supplement
                                                                           1     Describe mitosis as nuclear division giving rise to
                                                                                 genetically identical cells (details of the stages of
                                                                                 mitosis are not required)
                                                                           2     State the role of mitosis in growth, repair of
                                                                                 damaged tissues, replacement of cells and
                                                                                 asexual reproduction
                                                                           3     State that the exact replication of chromosomes
                                                                                 occurs before mitosis
                                                                           4     State that during mitosis, the copies of
                                                                                 chromosomes separate, maintaining the
                                                                                 chromosome number in each daughter cell
                                                                           5     Describe stem cells as unspecialised cells that
                                                                                 divide by mitosis to produce daughter cells that
                                                                                 can become specialised for specific functions
17.3 Meiosis
           Core                                                           Supplement
                                                                          1   State that meiosis is involved in the production
                                                                              of gametes
                                                                          2   Describe meiosis as a reduction division in which
                                                                              the chromosome number is halved from diploid
                                                                              to haploid resulting in genetically different cells
                                                                              (details of the stages of meiosis are not required)
           Core                                                           Supplement
           1   Describe inheritance as the transmission
               of genetic information from generation to
               generation
           2   Describe genotype as the genetic make-up of an
               organism and in terms of the alleles present
           3   Describe phenotype as the observable features of
               an organism
           4   Describe homozygous as having two identical
               alleles of a particular gene
           5   State that two identical homozygous individuals
               that breed together will be pure-breeding
           6   Describe heterozygous as having two different
               alleles of a particular gene
           7   State that a heterozygous individual will not be
               pure-breeding
           8   Describe a dominant allele as an allele that is
               expressed if it is present in the genotype
           9   Describe a recessive allele as an allele that is only
               expressed when there is no dominant allele of
               the gene present in the genotype
           10 Interpret pedigree diagrams for the inheritance of
              a given characteristic
           11 Use genetic diagrams to predict the results of              13 Explain how to use a test cross to identify an
              monohybrid crosses and calculate phenotypic                    unknown genotype
              ratios, limited to 1 : 1 and 3 : 1 ratios
           12 Use Punnett squares in crosses which result in
              more than one genotype to work out and show
              the possible different genotypes                                                                           continued
           Core                                                            Supplement
                                                                           14 Describe codominance as a situation in
                                                                              which both alleles in heterozygous organisms
                                                                              contribute to the phenotype
                                                                           15 Explain the inheritance of ABO blood groups:
                                                                              phenotypes are A, B, AB and O blood groups and
                                                                              alleles are IA, IB and Io
                                                                           16 Describe a sex-linked characteristic as a feature
                                                                              in which the gene responsible is located on
                                                                              a sex chromosome and that this makes the
                                                                              characteristic more common in one sex than in
                                                                              the other
                                                                           17 Describe red-green colour blindness as an
                                                                              example of sex linkage
                                                                           18 Use genetic diagrams to predict the results of
                                                                              monohybrid crosses involving codominance or
                                                                              sex linkage and calculate phenotypic ratios
           Core                                                            Supplement
           1    Describe variation as differences between
                individuals of the same species
           2    State that continuous variation results in a range
                of phenotypes between two extremes; examples
                include body length and body mass
           3    State that discontinuous variation results
                in a limited number of phenotypes with no
                intermediates; examples include ABO blood
                groups, seed shape in peas and seed colour in
                peas
           4    State that discontinuous variation is usually
                caused by genes only and continuous variation is
                caused by both genes and the environment
           5    Investigate and describe examples of continuous
                and discontinuous variation
           6    Describe mutation as genetic change                        9     Describe gene mutation as a random change in
                                                                                 the base sequence of DNA
           7    State that mutation is the way in which new                10 State that mutation, meiosis, random mating
                alleles are formed                                            and random fertilisation are sources of genetic
                                                                              variation in populations
           8    State that ionising radiation and some chemicals
                increase the rate of mutation
           Core                                                            Supplement
           1   Describe an adaptive feature as an inherited
               feature that helps an organism to survive and
               reproduce in its environment
           2   Interpret images or other information about a
               species to describe its adaptive features
                                                                           3   Explain the adaptive features of hydrophytes and
                                                                               xerophytes to their environments
18.3 Selection
           Core                                                            Supplement
           1   Describe natural selection with reference to:               4   Describe adaptation as the process, resulting
               (a) genetic variation within populations                        from natural selection, by which populations
                                                                               become more suited to their environment over
               (b) production of many offspring
                                                                               many generations
               (c)	struggle for survival, including competition
                    for resources
               (d)	a greater chance of reproduction by
                    individuals that are better adapted to the
                    environment than others
               (e)	these individuals pass on their alleles to the
                    next generation
                                                                           5   Describe the development of strains of antibiotic
                                                                               resistant bacteria as an example of natural
                                                                               selection
           2   Describe selective breeding with reference to:
               (a)	selection by humans of individuals with
                    desirable features
               (b)	crossing these individuals to produce the
                    next generation
               (c)	selection of offspring showing the desirable
                    features
           3   Outline how selective breeding by artificial                6   Outline the differences between natural and
               selection is carried out over many generations to               artificial selection
               improve crop plants and domesticated animals
               and apply this to given contexts
           Core                                                            Supplement
           1    State that the Sun is the principal source of
                energy input to biological systems
           2    Describe the flow of energy through living
                organisms, including light energy from the
                Sun and chemical energy in organisms, and its
                eventual transfer to the environment
           Core                                                            Supplement
           1    Describe a food chain as showing the transfer of
                energy from one organism to the next, beginning
                with a producer
           2    Construct and interpret simple food chains
           3    Describe a food web as a network of
                interconnected food chains and interpret food
                webs
           4    Describe a producer as an organism that makes
                its own organic nutrients, usually using energy
                from sunlight, through photosynthesis
           5    Describe a consumer as an organism that gets its
                energy by feeding on other organisms
           6    State that consumers may be classed as primary,
                secondary, tertiary and quaternary according to
                their position in a food chain
           7    Describe a herbivore as an animal that gets its
                energy by eating plants
           8    Describe a carnivore as an animal that gets its
                energy by eating other animals
           9    Describe a decomposer as an organism that gets
                its energy from dead or waste organic material
           10 Use food chains and food webs to describe the
              impact humans have through overharvesting of
              food species and through introducing foreign
              species to a habitat
           11 Draw, describe and interpret pyramids of                     15 Draw, describe and interpret pyramids of energy
              numbers and pyramids of biomass
           12 Discuss the advantages of using a pyramid of                 16 Discuss the advantages of using a pyramid of
              biomass rather than a pyramid of numbers to                     energy rather than pyramids of numbers or
              represent a food chain                                          biomass to represent a food chain
           13 Describe a trophic level as the position of an
              organism in a food chain, food web or ecological
              pyramid                                                                                                continued
           Core                                                       Supplement
           14 Identify the following as the trophic levels in
              food webs, food chains and ecological pyramids:
              producers, primary consumers, secondary
              consumers, tertiary consumers and quaternary
              consumers
                                                                      17 Explain why the transfer of energy from one
                                                                         trophic level to another is often not efficient
                                                                      18 Explain, in terms of energy loss, why food chains
                                                                         usually have fewer than five trophic levels
                                                                      19 Explain why it is more energy efficient for
                                                                         humans to eat crop plants than to eat livestock
                                                                         that have been fed on crop plants
           Core                                                       Supplement
           1   Describe the carbon cycle, limited to:
               photosynthesis, respiration, feeding,
               decomposition, formation of fossil fuels and
               combustion
                                                                      2   Describe the nitrogen cycle with reference to:
                                                                          •    decomposition of plant and animal protein to
                                                                               ammonium ions
                                                                          •    nitrification
                                                                          •    nitrogen fixation by lightning and bacteria
                                                                          •    absorption of nitrate ions by plants
                                                                          •    production of amino acids and proteins
                                                                          •    feeding and digestion of proteins
                                                                          •    deamination
                                                                          •    denitrification
                                                                      3   State the roles of microorganisms in the nitrogen
                                                                          cycle, limited to: decomposition, nitrification,
                                                                          nitrogen fixation and denitrification (generic
                                                                          names of individual bacteria, e.g. Rhizobium, are
                                                                          not required)
19.4 Populations
           Core                                                            Supplement
           1    Describe a population as a group of organisms of
                one species, living in the same area, at the same
                time
           2    Describe a community as all of the populations
                of different species in an ecosystem
           3    Describe an ecosystem as a unit containing the
                community of organisms and their environment,
                interacting together
           4    Identify and state the factors affecting the rate
                of population growth for a population of an
                organism, limited to food supply, competition,
                predation and disease
           5    Identify the lag, exponential (log), stationary            7     Explain the factors that lead to each phase in
                and death phases in the sigmoid curve of                         the sigmoid curve of population growth, making
                population growth for a population growing in an                 reference, where appropriate, to the role of
                environment with limited resources                               limiting factors
           6    Interpret graphs and diagrams of population
                growth
           Core                                                            Supplement
           1    Describe how humans have increased food
                production, limited to:
                (a)	agricultural machinery to use larger areas of
                     land and improve efficiency
                (b) chemical fertilisers to improve yields
                (c) insecticides to improve quality and yield
                (d) herbicides to reduce competition with weeds
                (e)	selective breeding to improve production by
                     crop plants and livestock
           2    Describe the advantages and disadvantages of
                large-scale monocultures of crop plants
           3    Describe the advantages and disadvantages of
                intensive livestock production
           Core                                                        Supplement
           1   Describe biodiversity as the number of different
               species that live in an area
           2   Describe the reasons for habitat destruction,
               including:
               (a)	increased area for housing, crop plant
                    production and livestock production
               (b) extraction of natural resources
               (c) freshwater and marine pollution
           3   State that through altering food webs and food
               chains, humans can have a negative impact on
               habitats
           4   Explain the undesirable effects of deforestation
               as an example of habitat destruction, to include:
               reducing biodiversity, extinction, loss of soil,
               flooding and increase of carbon dioxide in the
               atmosphere
20.3 Pollution
           Core                                                        Supplement
           1   Describe the effects of untreated sewage and            4   Explain the process of eutrophication of water,
               excess fertiliser on aquatic ecosystems                     limited to:
                                                                           •    increased availability of nitrate and other
                                                                                ions
                                                                           •    increased growth of producers
                                                                           •    increased decomposition after death of
                                                                                producers
                                                                           •    increased aerobic respiration by decomposers
                                                                           •    reduction in dissolved oxygen
                                                                           •    death of organisms requiring dissolved
                                                                                oxygen in water
           2   Describe the effects of non-biodegradable
               plastics, in both aquatic and terrestrial
               ecosystems
           3   Describe the sources and effects of pollution of
               the air by methane and carbon dioxide, limited
               to: the enhanced greenhouse effect and climate
               change
20.4 Conservation
           Core                                                            Supplement
           1    Describe a sustainable resource as one which is
                produced as rapidly as it is removed from the
                environment so that it does not run out
           2    State that some resources can be conserved and             5     Explain how forests can be conserved using:
                managed sustainably, limited to forests and fish                 education, protected areas, quotas and replanting
                stocks                                                     6     Explain how fish stocks can be conserved using:
                                                                                 education, closed seasons, protected areas,
                                                                                 controlled net types and mesh size, quotas and
                                                                                 monitoring
           3    Explain why organisms become endangered
                or extinct, including: climate change, habitat
                destruction, hunting, overharvesting, pollution
                and introduced species
           4    Describe how endangered species can be                     7     Describe the reasons for conservation
                conserved, limited to:                                           programmes, limited to:
                (a)	monitoring and protecting species and                       (a) maintaining or increasing biodiversity
                     habitats                                                    (b) reducing extinction
                (b) education                                                    (c) protecting vulnerable ecosystems
                (c) captive breeding programmes                                  (d)	maintaining ecosystem functions, limited
                (d) seed banks                                                        to nutrient cycling and resource provision,
                                                                                      including food, drugs, fuel and genes
                                                                           8     Describe the use of artificial insemination (AI)
                                                                                 and in vitro fertilisation (IVF) in captive breeding
                                                                                 programmes
                                                                           9     Explain the risks to a species if its population size
                                                                                 decreases, reducing genetic variation (knowledge
                                                                                 of genetic drift is not required)
           Core                                                            Supplement
           1    State that bacteria are useful in biotechnology            2     Discuss why bacteria are useful in biotechnology
                and genetic modification due to their rapid                      and genetic modification, limited to:
                reproduction rate and their ability to make                      (a)	few ethical concerns over their manipulation
                complex molecules                                                     and growth
                                                                                 (b)	the presence of plasmids
21.2 Biotechnology
           Core                                                         Supplement
           1   Describe the role of anaerobic respiration in yeast
               during the production of ethanol for biofuels
           2   Describe the role of anaerobic respiration in yeast
               during bread-making
           3   Describe the use of pectinase in fruit juice
               production
           4   Investigate and describe the use of biological
               washing powders that contain enzymes
                                                                        5   Explain the use of lactase to produce lactose-free
                                                                            milk
                                                                        6   Describe how fermenters can be used for the
                                                                            large-scale production of useful products by
                                                                            bacteria and fungi, including insulin, penicillin and
                                                                            mycoprotein
                                                                        7   Describe and explain the conditions that need to be
                                                                            controlled in a fermenter, including: temperature,
                                                                            pH, oxygen, nutrient supply and waste products
           Core                                                         Supplement
           1   Describe genetic modification as changing the            3   Outline the process of genetic modification using
               genetic material of an organism by removing,                 bacterial production of a human protein as an
               changing or inserting individual genes                       example, limited to:
                                                                            (a)	isolation of the DNA making up a human
                                                                                 gene using restriction enzymes, forming
                                                                                 sticky ends
                                                                            (b)	cutting of bacterial plasmid DNA with
                                                                                 the same restriction enzymes, forming
                                                                                 complementary sticky ends
                                                                            (c)	insertion of human DNA into bacterial
                                                                                 plasmid DNA using DNA ligase to form a
                                                                                 recombinant plasmid
                                                                            (d)	insertion of recombinant plasmids into
                                                                                 bacteria (specific details are not required)
                                                                            (e)	multiplication of bacteria containing
                                                                                 recombinant plasmids
                                                                            (f)	expression in bacteria of the human gene to
                                                                                 make the human protein
                                                                                                                       continued
           Core                                                            Supplement
           2    Outline examples of genetic modification:
                (a)	the insertion of human genes into bacteria to
                     produce human proteins
                (b)	the insertion of genes into crop plants to
                     confer resistance to herbicides
                (c)	the insertion of genes into crop plants to
                     confer resistance to insect pests
                (d)	the insertion of genes into crop plants to
                     improve nutritional qualities
                                                                           4     Discuss the advantages and disadvantages of
                                                                                 genetically modifying crops, including soya,
                                                                                 maize and rice