Subject Content - A-Levels Biology

2c. Content of modules 1 to 6

The OCR A Level Biology A detailed content is arranged across six teaching modules. Practical skills are embedded throughout the content and assessed in written papers and through the Practical Endorsement.

Module 1: Development of practical skills in biology

The development of practical skills is a fundamental and integral aspect of the study of any scientific subject. These skills enhance learners' understanding of the subject and serve as suitable preparation for studying biology at a higher level.

1.1 Practical skills assessed in a written examination

Practical skills are embedded throughout all the content of this specification. Learners will be required to develop a range of practical skills throughout their course in preparation for the written examinations.

1.1.1 Planning

Ref.	Learning outcomes	Additional guidance
(a)	Experimental design, including to solve problems set in a practical context.	Including selection of suitable apparatus, equipment and techniques for the proposed experiment. Learners should be able to apply scientific knowledge based on the content of the specification to the practical context. HSW3
(b)	Identification of variables that must be controlled, where appropriate.
(c)	Evaluation that an experimental method is appropriate to meet the expected outcomes.	HSW6

1.1.2 Implementing

Ref.	Learning outcomes	Additional guidance
(a)	How to use a wide range of practical apparatus and techniques correctly.	As outlined in the content of the specification and the skills required for the Practical Endorsement. HSW4
(b)	Appropriate units for measurements.	M0.1
(c)	Presenting observations and data in an appropriate format.	HSW8

1.1.3 Analysis

Ref.	Learning outcomes	Additional guidance
(a)	Processing, analysing and interpreting qualitative and quantitative experimental results.	Including reaching valid conclusions, where appropriate. HSW5
(b)	Use of appropriate mathematical skills for analysis of quantitative data.	Refer to Section 5d for a list of mathematical skills that learners should have acquired competence in as part of their course. HSW3
(c)	Appropriate use of significant figures.	M1.1
(d)	Plotting and interpreting suitable graphs from experimental results, including: (i) selection and labelling of axes with appropriate scales, quantities and units; (ii) measurement of gradients and intercepts.	(i) M3.2 (ii) M3.3, M3.4, M3.5

1.1.4 Evaluation

Ref.	Learning outcomes	Additional guidance
(a)	How to evaluate results and draw conclusions.	HSW6
(b)	The identification of anomalies in experimental measurements.
(c)	The limitations in experimental procedures.
(d)	Precision and accuracy of measurements and data, including margins of error, percentage errors and uncertainties in apparatus.	M1.11
(e)	The refining of experimental design by suggestion of improvements to the procedures and apparatus.	HSW3

1.2 Practical skills assessed in the practical endorsement

A range of practical experiences is a vital part of a learner's development as part of this course. Learners should develop and practise a wide range of practical skills throughout the course as preparation for the Practical Endorsement, as well as for the written examinations.

The experiments and skills required for the Practical Endorsement will allow learners to develop and practise their practical skills, preparing learners for the written examinations. Please refer to Section 5f in this specification to see the list of practical experiences all learners should cover during their course.

1.2.1 Practical skills

Ref.	Learning outcomes	Additional guidance
Independent thinking
(a)	Apply investigative approaches and methods to practical work.	Including how to solve problems in a practical context. HSW3
Use and application of scientific methods and practices
(b)	Safely and correctly use a range of practical equipment and materials.	See Section 5f. Including identification of potential hazards. Learners should understand how to minimise the risks involved. HSW4
(c)	Follow written instructions.
(d)	Make and record observations/measurements.	HSW8
(e)	Keep appropriate records of experimental activities.	See Section 5f.
(f)	Present information and data in a scientific way.	HSW8
(g)	Use appropriate software and tools to process data, carry out research and report findings.	M3.1 HSW3
Research and referencing
(h)	Use online and offline research skills including websites, textbooks and other printed scientific sources of information.
(i)	Correctly cite sources of information.	The Practical Skills Handbook provides guidance on appropriate methods for citing information.
Instruments and equipment
(j)	Use a wide range of experimental and practical instruments, equipment and techniques appropriate to the knowledge and understanding included in the specification.	See Section 5f. HSW4

1.2.2 Use of apparatus and techniques

Ref.	Learning outcomes	Additional guidance
(a)	Use of appropriate apparatus to record a range of quantitative measurements (to include mass, time, volume, temperature, length and pH).	HSW4
(b)	Use of appropriate instrumentation to record quantitative measurements, such as a colorimeter or potometer.	HSW4
(c)	Use of laboratory glassware apparatus for a variety of experimental techniques to include serial dilutions.	HSW4
(d)	Use of a light microscope at high power and low power, including use of a graticule.	HSW4
(e)	Production of scientific drawings from observations with annotations.	HSW8
(f)	Use of qualitative reagents to identify biological molecules.	HSW4
(g)	Separation of biological compounds using thin layer/paper chromatography or electrophoresis.	HSW4
(h)	Safe and ethical use of organisms to measure: (i) plant or animal responses; (ii) physiological functions.	HSW4, HSW10
(i)	Use of microbiological aseptic techniques, including the use of agar plates and broth.	HSW4
(j)	Safe use of instruments for dissection of an animal or plant organ.	HSW4
(k)	Use of sampling techniques in fieldwork.	HSW4
(l)	Use of ICT such as computer modelling, or a data logger to collect data, or use of software to process data.	HSW3, HSW4

Module 2: Foundations in biology

All living organisms have similarities in cellular structure, biochemistry and function. This module gives learners the opportunity to use microscopy to study cell structure, biological molecules, membranes, enzymes, nucleic acids, cell division and stem cells.

2.1 Foundations in biology

2.1.1 Cell structure

Ref.	Learning outcomes	Additional guidance
(a)	The use of microscopy to observe and investigate different types of cell and cell structure in a range of eukaryotic organisms.	To include an appreciation of images produced by light microscopes, transmission electron microscopes and scanning electron microscopes. HSW1, HSW7
(b)	The preparation and examination of microscope slides for use in light microscopy.	Including the use of an eye piece graticule and stage micrometer. PAG1 HSW4
(c)	The use of staining in light microscopy.	To include differential staining to identify different cellular components and cell types. PAG1 HSW4, HSW5
(d)	The representation of cell structure as seen under the light microscope using drawings and annotated diagrams of whole cells or cells in sections of tissue.	PAG1
(e)	The use and manipulation of the magnification formula.	$\text{magnification} = \frac{\text{size of image}}{\text{size of real object}}$ M0.1, M0.2, M0.3, M1.1, M1.8, M2.2, M2.3, M2.4
(f)	The difference between magnification and resolution.	To include an appreciation of the differences in resolution and magnification that can be achieved by a light microscope, transmission electron microscope and scanning electron microscope. Learners are not required to recall exact resolutions or magnification numbers. M0.2, M0.3 HSW7, HSW8
(g)	The ultrastructure of eukaryotic cells and the functions of the different cellular components.	To include nucleus, nucleolus, nuclear envelope, rough and smooth ER, Golgi apparatus, ribosomes, mitochondria, lysosomes, chloroplasts, plasma membrane, centrioles, cell wall, flagella and cilia. M0.2
(h)	Photomicrographs of cellular components in a range of eukaryotic cells.	To include interpretation of transmission and scanning electron microscope images.
(i)	The interrelationship between the organelles involved in the production and secretion of proteins.
(j)	The importance of the cytoskeleton.	To include providing mechanical strength to cells, aiding transport within cells and enabling cell movement. HSW2
(k)	The similarities and differences in the structure and ultrastructure of prokaryotic and eukaryotic cells.	PAG1

2.1.2 Biological molecules

Ref.	Learning outcomes	Additional guidance
(a)	How hydrogen bonding occurs between water molecules, and relate this, and other properties of water, to the roles of water for living organisms.	To include roles that relate to the properties of water: solvent, transport medium, coolant and habitat, illustrated using examples of prokaryotes and eukaryotes. HSW2, HSW8
(b)	The concept of monomers and polymers and the importance of condensation and hydrolysis reactions in a range of biological molecules.
(c)	The chemical elements that make up biological molecules.	To include C, H and O for carbohydrates; C, H and O for lipids; C, H, O, N and S for proteins; C, H, O, N and P for nucleic acids.
(d)	The ring structure and properties of glucose as an example of a hexose monosaccharide and the structure of ribose as an example of a pentose monosaccharide.	To include the structural difference between an alpha- and a beta-glucose molecule and the difference between a hexose and a pentose monosaccharide.
(e)	The synthesis and breakdown of a disaccharide and polysaccharide by the formation and breakage of glycosidic bonds.	To include sucrose, lactose and maltose.
(f)	The structure of starch (amylose and amylopectin), glycogen and cellulose molecules.	HSW8
(g)	How the structures and properties of glucose, starch, glycogen and cellulose molecules relate to their functions in living organisms.	HSW2, HSW8
(h)	The structure of a triglyceride and a phospholipid as examples of macromolecules.	To include the structure of saturated and unsaturated fatty acids.
(i)	The synthesis and breakdown of triglycerides by the formation and breakage of ester bonds between fatty acids and glycerol.
(j)	How the properties of triglyceride, phospholipid and cholesterol molecules relate to their functions in living organisms.	To include hydrophobic and hydrophilic regions and energy content. Learners should apply this in prokaryote and eukaryote contexts. HSW2, HSW8
(k)	The general structure of an amino acid.
(l)	The synthesis and breakdown of dipeptides and polypeptides, by the formation and breakage of peptide bonds.
(m)	The levels of protein structure.	To include primary, secondary, tertiary and quaternary structure; hydrogen bonding, hydrophobic and hydrophilic interactions, disulfide bonds and ionic bonds. HSW8
(n)	The structure and function of globular proteins including a conjugated protein.	To include haemoglobin as an example of a conjugated protein, a named enzyme and insulin. PAG10
(o)	The properties and functions of fibrous proteins.	To include collagen, keratin and elastin; no structural detail required.
(p)	The key inorganic ions that are involved in biological processes.	To include calcium ions ( $\mathrm{Ca^{2+}}$ ), sodium ions ( $\mathrm{Na^+}$ ), potassium ions ( $\mathrm{K^+}$ ), hydrogen ions ( $\mathrm{H^+}$ ), ammonium ions ( $\mathrm{NH_4^+}$ ), nitrate ( $\mathrm{NO_3^-}$ ), hydrogencarbonate ( $\mathrm{HCO_3^-}$ ), chloride ( $\mathrm{Cl^-}$ ), phosphate ( $\mathrm{PO_4^{3-}}$ ), hydroxide ( $\mathrm{OH^-}$ ).
(q)	How to carry out and interpret the results of the biuret test for proteins, Benedict's test for reducing and non-reducing sugars, iodine test for starch and emulsion test for lipids.	PAG9 HSW3, HSW4, HSW5
(r)	Quantitative methods to determine the concentration of a chemical substance in a solution.	To include colorimetry. PAG5 HSW3, HSW4, HSW5
(s)(i)	The principles and uses of paper and thin layer chromatography to separate biological molecules / compounds.	To include calculation of Rf values: $Rf = \frac{\text{distance moved by the solute}}{\text{distance moved by the solvent}}$ .
(s)(ii)	Practical investigations to analyse biological solutions using paper or thin layer chromatography.	Learners should apply this in the context of separating proteins, carbohydrates, vitamins and nucleic acids. M0.1, M0.2, M1.1, M1.3, M2.2, M2.3, M2.4 PAG6 HSW2, HSW3, HSW4

2.1.3 Nucleotides and nucleic acids

Ref.	Learning outcomes	Additional guidance
(a)	The structure of a nucleotide as the monomer from which nucleic acids are made.	To include differences between RNA and DNA nucleotides, purines and pyrimidines and the type of pentose sugar. PAG10
(b)	The synthesis and breakdown of polynucleotides by the formation and breakage of phosphodiester bonds.
(c)	The structure of ADP and ATP as phosphorylated nucleotides.	Comprising a pentose sugar (ribose), a nitrogenous base (adenine) and inorganic phosphates.
(d)(i)	The structure of DNA (deoxyribonucleic acid).	To include hydrogen bonding between complementary base pairs (A to T, G to C) on two antiparallel DNA polynucleotides and how twisting produces the double-helix shape.
(d)(ii)	Practical investigations into the purification of DNA by precipitation.	PAG9 HSW3, HSW4
(e)	Semi-conservative DNA replication.	To include helicase, DNA polymerase, conserving genetic information accurately and random spontaneous mutations. AS learners are not required to distinguish mutation types. HSW8
(f)	The nature of the genetic code.	To include triplet, non-overlapping, degenerate and universal nature of the code and how a gene determines amino acid sequence.
(g)	Transcription and translation of genes resulting in the synthesis of polypeptides.	To include RNA polymerase, mRNA, tRNA and rRNA. HSW8

2.1.4 Enzymes

Ref.	Learning outcomes	Additional guidance
(a)	The role of enzymes in catalysing reactions that affect metabolism at a cellular and whole organism level.	To include the idea that enzymes affect both structure and function.
(b)	The role of enzymes in catalysing both intracellular and extracellular reactions.	To include catalase as intracellular and amylase as extracellular examples.
(c)	The mechanism of enzyme action.	To include tertiary structure, specificity, active site, lock and key hypothesis, induced-fit hypothesis, enzyme-substrate complex, enzyme-product complex, product formation and lowering of activation energy. HSW1, HSW8
(d)(i)	The effects of pH, temperature, enzyme concentration and substrate concentration on enzyme activity.	To include temperature coefficient $Q_{10} = \frac{R_2}{R_1}$ .
(d)(ii)	Practical investigations into the effects of pH, temperature, enzyme concentration and substrate concentration on enzyme activity.	An opportunity for serial dilutions. M0.1, M0.2, M0.3, M1.1, M1.3, M1.11, M3.1, M3.2, M3.3, M3.5, M3.6 PAG4 HSW1, HSW2, HSW4, HSW5, HSW6, HSW8
(e)	The need for coenzymes and cofactors in some enzyme-controlled reactions.	To include chloride ion as a cofactor for amylase and vitamins as a source of coenzymes. PAG4
(f)	The effects of inhibitors on the rate of enzyme-controlled reactions.	To include competitive and non-competitive, reversible and non-reversible inhibitors, and end-product inhibition. M0.1, M0.2, M0.3, M1.1, M1.3, M1.11, M3.1, M3.2, M3.3, M3.5, M3.6 PAG4 HSW1, HSW2, HSW4, HSW5, HSW6, HSW8

2.1.5 Biological membranes

Ref.	Learning outcomes	Additional guidance
(a)	The roles of membranes within cells and at the surface of cells.	To include partially permeable barriers, sites of chemical reactions and sites of cell communication.
(b)	The fluid mosaic model of membrane structure and the roles of its components.	To include phospholipids, cholesterol, glycolipids, proteins, glycoproteins and membrane-bound receptors where hormones and drugs bind. M0.2 HSW1
(c)(i)	Factors affecting membrane structure and permeability.	To include effects of temperature and solvents.
(c)(ii)	Practical investigations into factors affecting membrane structure and permeability.	M0.1, M0.2, M1.1, M1.2, M1.3, M1.6, M1.11, M3.1, M3.2, M3.3, M3.5, M3.6 PAG5, PAG8 HSW1, HSW2, HSW3, HSW4, HSW5, HSW6
(d)(i)	The movement of molecules across membranes.	To include diffusion and facilitated diffusion as passive methods; active transport, endocytosis and exocytosis requiring ATP.
(d)(ii)	Practical investigations into the factors affecting diffusion rates in model cells.	M0.1, M0.2, M0.3, M1.1, M1.2, M1.3, M1.6, M1.11, M2.1, M3.1, M3.2, M3.3, M3.5, M3.6, M4.1 PAG8 HSW1, HSW2, HSW3, HSW4, HSW5, HSW6
(e)(i)	The movement of water across membranes by osmosis and the effects that solutions of different water potential can have on plant and animal cells.	Osmosis to be explained in terms of a water potential gradient across a partially permeable membrane.
(e)(ii)	Practical investigations into the effects of solutions of different water potential on plant and animal cells.	M0.1, M0.2, M0.3, M1.1, M1.2, M1.3, M1.6, M1.10, M1.11, M2.1, M3.1, M3.2, M4.1 PAG8 HSW1, HSW2, HSW3, HSW4, HSW5, HSW6

2.1.6 Cell division, cell diversity and cellular organisation

Ref.	Learning outcomes	Additional guidance
(a)	The cell cycle.	To include interphase (G1, S and G2), mitosis and cytokinesis leading to genetically identical cells. HSW8
(b)	How the cell cycle is regulated.	To include an outline of checkpoints.
(c)	The main stages of mitosis.	To include changes in nuclear envelope, chromosomes, chromatids, centromere, centrioles, spindle fibres and cell membrane. HSW8
(d)	Sections of plant tissue showing the cell cycle and stages of mitosis.	To include stained sections and squashes of plant tissue and labelled diagrams. PAG1
(e)	The significance of mitosis in life cycles.	To include growth, tissue repair and asexual reproduction in plants, animals and fungi. HSW2
(f)	The significance of meiosis in life cycles.	To include haploid cell production and genetic variation by independent assortment and crossing over. HSW2, HSW5
(g)	The main stages of meiosis.	To include interphase, prophase 1, metaphase 1, anaphase 1, telophase 1, prophase 2, metaphase 2, anaphase 2, telophase 2 and homologous chromosomes. PAG1 HSW8
(h)	How cells of multicellular organisms are specialised for particular functions.	To include erythrocytes, neutrophils, squamous and ciliated epithelial cells, sperm cells, palisade cells, root hair cells and guard cells. PAG1
(i)	The organisation of cells into tissues, organs and organ systems.	To include squamous and ciliated epithelia, cartilage, muscle, xylem and phloem as examples of tissues.
(j)	The features and differentiation of stem cells.	To include stem cells as a renewing source of undifferentiated cells.
(k)	The production of erythrocytes and neutrophils as examples of distinct, differentiated cells derived from a common stem cell in bone marrow.
(l)	The production of xylem vessels and phloem sieve tubes as examples of distinct, differentiated outcomes derived from a common stem cell in meristems.
(m)	The potential uses of stem cells in research and medicine.	To include repair of damaged tissues, treatment of neurological conditions and research into developmental biology. HSW2, HSW5, HSW6, HSW7, HSW9, HSW10, HSW11, HSW12

Module 3: Exchange and transport

In this module, learners study the structure and function of gas exchange and transport systems in a range of animals and in terrestrial plants. The significance of surface area to volume ratio is emphasised.

3.1 Exchange and transport

3.1.1 Exchange surfaces

Ref.	Learning outcomes	Additional guidance
(a)	The need for specialised exchange surfaces.	To include surface area to volume ratio (SA:V), metabolic activity, single-celled and multicellular organisms. $\text{ratio} = \frac{\text{surface area}}{\text{volume}}$ . M0.1, M0.3, M0.4, M1.1, M2.1, M4.1 HSW1, HSW3, HSW5, HSW8
(b)	The features of an efficient exchange surface.	To include increased surface area (root hair cells), thin layer (alveoli), good blood supply/ventilation to maintain gradient (gills/alveolus).
(c)	The structures and functions of the components of the mammalian gaseous exchange system.	To include cartilage, ciliated epithelium, goblet cells, smooth muscle and elastic fibres in the trachea, bronchi, bronchioles and alveoli. PAG1 HSW8
(d)	The mechanism of ventilation in mammals.	To include rib cage, intercostal muscles and diaphragm. HSW8
(e)	The relationship between vital capacity, tidal volume, breathing rate and oxygen uptake.	To include analysis and interpretation of primary and secondary data from a data logger or spirometer. M0.1, M0.2, M0.4, M1.3 PAG10 HSW2, HSW3, HSW4, HSW5, HSW6
(f)	The mechanisms of ventilation and gas exchange in bony fish and insects.	To include bony fish buccal cavity volume changes, operculum, gill filaments, gill lamellae, countercurrent flow; insects: spiracles, trachea, thoracic and abdominal movement, exchange with tracheal fluid. HSW8
(g)	The dissection, examination and drawing of the gaseous exchange system of a bony fish and/or insect trachea.	PAG2 HSW4
(h)	The examination of microscope slides to show the histology of exchange surfaces.	PAG1 HSW4

3.1.2 Transport in animals

Ref.	Learning outcomes	Additional guidance
(a)	The need for transport systems in multicellular animals.	To include size, metabolic rate and surface area to volume ratio (SA:V). M0.1, M0.3, M0.4, M1.1, M2.1, M4.1 HSW1, HSW3, HSW5, HSW8
(b)	The different types of circulatory systems.	To include single, double, open and closed circulatory systems in insects, fish and mammals.
(c)	The structure and functions of arteries, arterioles, capillaries, venules and veins.	To include distribution of different tissues within vessel walls. PAG2
(d)	The formation of tissue fluid from plasma.	To include hydrostatic pressure, oncotic pressure and differences in the composition of blood, tissue fluid and lymph. HSW8
(e)(i)	The external and internal structure of the mammalian heart.	PAG2 HSW4
(e)(ii)	The dissection, examination and drawing of the external and internal structure of the mammalian heart.
(f)	The cardiac cycle.	To include the role of valves and pressure changes in the heart and associated vessels. $\text{cardiac output} = \text{heart rate} \times \text{stroke volume}$ . HSW2, HSW5, HSW8
(g)	How heart action is initiated and coordinated.	To include sino-atrial node (SAN), atrio-ventricular node (AVN), Purkyne tissue and myogenic nature of cardiac muscle. HSW2, HSW5, HSW8
(h)	The use and interpretation of electrocardiogram (ECG) traces.	To include normal and abnormal heart activity: tachycardia, bradycardia, fibrillation and ectopic heartbeat only. M0.1, M1.1, M1.3, M2.4 HSW2, HSW5
(i)	The role of haemoglobin in transporting oxygen and carbon dioxide.	To include reversible oxygen binding, carbonic anhydrase, haemoglobinic acid, hydrogencarbonate ion and chloride shift. HSW8
(j)	The oxygen dissociation curve for fetal and adult human haemoglobin.	To include different affinities for oxygen and Bohr effect changes at different carbon dioxide concentrations. M3.1 HSW2, HSW8

3.1.3 Transport in plants

Ref.	Learning outcomes	Additional guidance
(a)	The need for transport systems in multicellular plants.	To include size, metabolic rate and surface area to volume ratio (SA:V). M0.1, M0.3, M0.4, M1.1, M2.1, M4.1 HSW1, HSW3, HSW5, HSW8
(b)(i)	The structure and function of the vascular system in the roots, stems and leaves of herbaceous dicotyledonous plants.	To include xylem vessels, sieve tube elements and companion cells.
(b)(ii)	The examination and drawing of stained sections of plant tissue to show the distribution of xylem and phloem.	PAG1 HSW4
(b)(iii)	The dissection of stems, both longitudinally and transversely, and their examination to demonstrate the position and structure of xylem vessels.	PAG2 HSW4
(c)(i)	The process of transpiration and the environmental factors that affect transpiration rate.	To include transpiration as a consequence of gaseous exchange.
(c)(ii)	Practical investigations to estimate transpiration rates.	To include a potometer. M0.1, M0.2, M1.1, M1.2, M1.3, M1.6, M1.11, M3.1, M3.2, M3.3, M3.5, M3.6, M4.1 PAG5, PAG11 HSW2, HSW3, HSW4, HSW5, HSW6, HSW8
(d)	The transport of water into the plant, through the plant and to the air surrounding the leaves.	To include apoplast and symplast pathways and movement in terms of water potential, adhesion, cohesion and transpiration stream. HSW2, HSW8
(e)	Adaptations of plants to the availability of water in their environment.	To include xerophytes (cacti and marram grass) and hydrophytes (water lilies). HSW2
(f)	The mechanism of translocation.	To include translocation as an energy-requiring process transporting assimilates, especially sucrose, in the phloem between sources and sinks; active loading at the source and removal at the sink. HSW2, HSW8

Module 4: Biodiversity, evolution and disease

In this module learners study biodiversity, classification, disease, immune responses, conservation, evolution and the impacts of pathogens on disease treatment.

4.1 Communicable diseases, disease prevention and the immune system

4.1.1 Communicable diseases, disease prevention and the immune system

Ref.	Learning outcomes	Additional guidance
(a)	The different types of pathogen that can cause communicable diseases in plants and animals.	To include bacteria: tuberculosis and ring rot; viruses: HIV/AIDS, influenza, Tobacco Mosaic Virus; protoctista: malaria, potato/tomato late blight; fungi: black sigatoka and athlete's foot. Binomial names are not required.
(b)	The means of transmission of animal and plant communicable pathogens.	To include methods of transmission with reference to vectors, spores and living conditions such as climate and social factors. Symptoms and direct/indirect categorisation are not required. M0.1, M0.2, M0.3, M1.1, M1.2, M1.3, M1.5, M1.7, M3.1, M3.2 HSW1, HSW2, HSW3, HSW5, HSW6, HSW7, HSW8, HSW11, HSW12
(c)	Plant defences against pathogens.	To include production of chemicals and plant responses that limit pathogen spread, e.g. callose deposition.
(d)	The primary non-specific defences against pathogens in animals.	To include skin, blood clotting, wound repair, inflammation, expulsive reflexes and mucous membranes. Names of clotting factors/all cascade steps and skin structure details are not required. HSW2, HSW8
(e)(i)	The structure and mode of action of phagocytes.	To include neutrophils and antigen-presenting cells, cytokines, opsonins, phagosomes and lysosomes.
(e)(ii)	Examination and drawing of cells observed in blood smears.	PAG1 HSW4, HSW8
(f)	The structure, different roles and modes of action of B and T lymphocytes in the specific immune response.	To include cell signalling, interleukins, clonal selection and expansion, plasma cells, T helper cells and T killer cells. HSW8
(g)	The primary and secondary immune responses.	To include T memory cells and B memory cells. M1.3 HSW2
(h)	The structure and general functions of antibodies.	To include the general protein structure of an antibody molecule.
(i)	An outline of the action of opsonins, agglutinins and anti-toxins.
(j)	The differences between active and passive immunity, and between natural and artificial immunity.	To include examples of each type of immunity.
(k)	Autoimmune diseases.	To include the term autoimmune disease and arthritis as a named example.
(l)	The principles of vaccination and the role of vaccination programmes in the prevention of epidemics.	To include routine vaccinations and reasons for changes to vaccines and programmes, including global issues. M0.1, M0.2, M0.3, M1.1, M1.2, M1.3, M1.5, M1.7, M3.1, M3.2 HSW1, HSW2, HSW3, HSW5, HSW6, HSW7, HSW8, HSW9, HSW11, HSW12
(m)	Possible sources of medicines.	To include microorganisms and plants, the need to maintain biodiversity and the potential for personalised medicines. HSW7, HSW9, HSW11, HSW12
(n)	The benefits and risks of using antibiotics to manage bacterial infection.	To include wide use following penicillin's discovery and the increase in bacterial resistance and its implications. HSW2, HSW5, HSW9, HSW12

4.2 Biodiversity

4.2.1 Biodiversity

Ref.	Learning outcomes	Additional guidance
(a)	How biodiversity may be considered at different levels.	To include habitat biodiversity, species biodiversity and genetic biodiversity.
(b)(i)	How sampling is used in measuring the biodiversity of a habitat and the importance of sampling.	To include random sampling, non-random sampling (opportunistic, stratified and systematic), the importance of sampling the range of organisms and techniques including quadrats, sweep nets, pitfall traps and pooters.
(b)(ii)	Practical investigations collecting random and non-random samples in the field.	M0.2, M1.3, M1.5, M1.4, M1.6, M1.7, M1.9, M1.10, M3.2 PAG3 HSW4, HSW5, HSW6
(c)	How to measure species richness and species evenness in a habitat.	M1.1, M1.5, M2.3, M2.4
(d)	The use and interpretation of Simpson's Index of Diversity (D) to calculate biodiversity of a habitat.	Formula provided where needed: $D = 1 - \sum\left(\frac{n}{N}\right)^2$ . Interpret high and low values. M1.1, M1.5, M2.3, M2.4 HSW5
(e)	How genetic biodiversity may be assessed, including calculations.	$\text{proportion of polymorphic gene loci} = \frac{\text{number of polymorphic gene loci}}{\text{total number of loci}}$ . Suitable populations include zoos, rare breeds and pedigree animals. M1.1, M1.5, M2.3, M2.4 HSW5
(f)	The factors affecting biodiversity.	To include human population growth, agriculture (monoculture) and climate change. M1.3, M1.7, M3.1 HSW5, HSW10, HSW12
(g)	The ecological, economic and aesthetic reasons for maintaining biodiversity.	Ecological: keystone species and genetic resource. Economic: reducing soil depletion. Aesthetic: protecting landscapes. HSW12
(h)	In situ and ex situ methods of maintaining biodiversity.	In situ: marine conservation zones and wildlife reserves. Ex situ: seed banks, botanic gardens and zoos. HSW7, HSW9, HSW10, HSW12
(i)	International and local conservation agreements made to protect species and habitats.	Historic and/or current agreements including CITES, Rio Convention on Biological Diversity and Countryside Stewardship Scheme. HSW11, HSW12

4.2.2 Classification and evolution

Ref.	Learning outcomes	Additional guidance
(a)	The biological classification of species.	To include kingdom, phylum, class, order, family, genus, species and domain. HSW1, HSW5, HSW6, HSW7
(b)	The binomial system of naming species and the advantage of such a system.
(c)(i)	The features used to classify organisms into five kingdoms: Prokaryotae, Protoctista, Fungi, Plantae, Animalia.	To include use of similarities in observable features in original classification.
(c)(ii)	The evidence that has led to new classification systems, such as the three domains of life, which clarifies relationships.	To include similarities in biological molecules and genetic evidence, details of three domains and comparison of kingdom and domain systems. HSW1, HSW5, HSW6, HSW7, HSW11, HSW12
(d)	The relationship between classification and phylogeny.	Learners are not required to know cladistics. HSW5, HSW7
(e)	The evidence for the theory of evolution by natural selection.	To include Darwin and Wallace, fossil, DNA (genomic DNA at AS) and molecular evidence. HSW1, HSW2, HSW5, HSW6, HSW7
(f)	The different types of variation.	To include intraspecific and interspecific variation; continuous and discontinuous variation with examples; genetic and environmental causes. M1.2, M1.3, M1.6, M1.7, M1.9, M1.10 HSW4
(g)	The different types of adaptations of organisms to their environment.	Anatomical, physiological and behavioural adaptations and why different taxonomic groups may show similar anatomical features. HSW5
(h)	The mechanism by which natural selection can affect the characteristics of a population over time.	To include genetic variation, selection pressure and reproductive success/failure increasing advantageous characteristics. M0.3 HSW8
(i)	How evolution in some species has implications for human populations.	To include pesticide resistance in insects and drug resistance in microorganisms. HSW8, HSW9, HSW12

Module 5: Communication, homeostasis and energy

This module covers response to stimuli, chemical and electrical communication, homeostasis, excretion, neuronal and hormonal communication, plant and animal responses, photosynthesis and respiration.

5.1 Communication and homeostasis

5.1.1 Communication and homeostasis

Ref.	Learning outcomes	Additional guidance
(a)	The need for communication systems in multicellular organisms.	To include animals and plants responding to internal and external changes and coordinating different organs.
(b)	The communication between cells by cell signalling.	To include signalling between adjacent cells and distant cells.
(c)	The principles of homeostasis.	To include receptors/effectors and negative/positive feedback. HSW8
(d)	The physiological and behavioural responses involved in temperature control in ectotherms and endotherms.	Endotherms: peripheral temperature receptors, hypothalamus, effectors in skin and muscles, behavioural responses. Ectotherms: behavioural responses. PAG11 HSW2

5.1.2 Excretion as an example of homeostatic control

Ref.	Learning outcomes	Additional guidance
(a)	The term excretion and its importance in maintaining metabolism and homeostasis.	To include removing metabolic wastes including carbon dioxide and nitrogenous waste.
(b)(i)	The structure and functions of the mammalian liver.	To include gross structure and histology, glycogen storage, detoxification and urea formation from ammonia and carbon dioxide as part of the ornithine cycle. Details of cycle not required.
(b)(ii)	The examination and drawing of stained sections to show histology of liver tissue.	PAG1 HSW4
(c)(i)	The structure, mechanisms of action and functions of the mammalian kidney.	To include gross structure and histology, detailed nephron and associated blood vessels, ultrafiltration, selective reabsorption and urine production.
(c)(ii)	The dissection, examination and drawing of the external and internal structure of the kidney.	M0.1, M0.3, M1.1, M1.3, M2.1, M3.1 PAG1, PAG2 HSW4, HSW6, HSW8
(c)(iii)	The examination and drawing of stained sections to show histology of nephrons.
(d)	The control of the water potential of the blood.	To include osmoreceptors in the hypothalamus, posterior pituitary gland, ADH and collecting duct walls. HSW8
(e)	The effects of kidney failure and its potential treatments.	To include GFR, electrolyte balance, haemodialysis and transplants. HSW7, HSW9, HSW12
(f)	How excretory products can be used in medical diagnosis.	To include urine samples in diagnostic tests, monoclonal antibodies in pregnancy testing and testing for anabolic steroids and drugs. PAG9 HSW7, HSW9, HSW11, HSW12

5.1.3 Neuronal communication

Ref.	Learning outcomes	Additional guidance
(a)	The roles of mammalian sensory receptors in converting different types of stimuli into nerve impulses.	To include sensory receptors such as Pacinian corpuscle responding to specific stimuli and acting as transducers.
(b)	The structure and functions of sensory, relay and motor neurones.	To include differences between myelinated and non-myelinated neurones.
(c)	The generation and transmission of nerve impulses in mammals.	To include resting potential, action potential generation with positive feedback, transmission in a myelinated neurone and frequency of impulse transmission. M1.3, M3.1
(d)	The structure and roles of synapses in neurotransmission.	To include cholinergic synapse structure, neurotransmitters, summation, inhibitory and excitatory synapses.

5.1.4 Hormonal communication

Ref.	Learning outcomes	Additional guidance
(a)	Endocrine communication by hormones.	To include secretion into blood, transport by blood and detection by target cells/tissues.
(b)	The structure and functions of the adrenal glands.	Adrenal glands as endocrine glands; hormones secreted by cortex and medulla and their functions.
(c)(i)	The histology of the pancreas.	To include endocrine tissues.
(c)(ii)	The examination and drawing of stained sections of the pancreas to show the histology of the endocrine tissues.	PAG1 HSW4
(d)	How blood glucose concentration is regulated.	To include insulin and glucagon as negative feedback, liver role, insulin secretion with potassium and calcium channels in beta cells. HSW12
(e)	The differences between Type 1 and Type 2 diabetes mellitus.	To include causes and treatments for each. HSW12
(f)	The potential treatments for diabetes mellitus.	To include insulin from genetically modified bacteria and potential stem cell use. HSW12

5.1.5 Plant and animal responses

Ref.	Learning outcomes	Additional guidance
(a)(i)	The types of plant responses.	Plant response to abiotic stress and herbivory. Herbivory response to include chemical defences (alkaloids and pheromones only), folding in response to touch and range of tropisms.
(a)(ii)	Practical investigations into phototropism and geotropism.	M1.3, M1.6 PAG11 HSW4
(b)	The roles of plant hormones.	To include leaf loss in deciduous plants, seed germination and stomatal closure.
(c)	The experimental evidence for the role of auxins in the control of apical dominance.	To include effects of auxin concentration. Learners apply knowledge to different experiments; specific experiments not required. HSW5
(d)	The experimental evidence for the role of gibberellin in the control of stem elongation and seed germination.	To include effects of gibberellin concentration; specific experiments not required. HSW5
(e)	Practical investigations into the effect of plant hormones on growth.	An opportunity for serial dilution. M0.2, M1.1, M1.2, M1.3, M1.4, M1.6, M1.9, M1.10, M3.1, M3.2 PAG11 HSW4
(f)	The commercial use of plant hormones.	To include control of ripening, rooting powders and hormonal weed killers. HSW12
(g)	The organisation of the mammalian nervous system.	To include central/peripheral systems and somatic/autonomic nervous systems.
(h)	The structure of the human brain and the functions of its parts.	To include gross structure and functions of cerebrum, cerebellum, medulla oblongata, hypothalamus and pituitary gland.
(i)	Reflex actions.	To include knee jerk reflex and survival value. M0.1, M0.2, M1.1, M1.2, M1.3, M1.6 PAG11 HSW4
(j)	The coordination of responses by the nervous and endocrine systems.	To include fight or flight response and hormone action in cell signalling with adrenaline, adenylyl cyclase and cyclic AMP.
(k)	The effects of hormones and nervous mechanisms on heart rate.	Opportunity to monitor physiological functions such as pulse rate or electrical activity. M0.1, M0.2, M0.3, M1.1, M1.2, M1.3, M1.6, M1.10, M3.1 PAG10, PAG11 HSW4
(l)(i)	The structure of mammalian muscle and the mechanism of muscular contraction.	To include skeletal, involuntary and cardiac muscle differences, neuromuscular junctions, sliding filament model, ATP role and creatine phosphate.
(l)(ii)	The examination of stained sections or photomicrographs of skeletal muscle.	PAG1, PAG10, PAG11 HSW4

5.2 Energy for biological processes

5.2.1 Photosynthesis

Ref.	Learning outcomes	Additional guidance
(a)	The interrelationship between the process of photosynthesis and respiration.	To include raw materials and products of the two processes. M0.1, M0.3, M0.4, M3.4
(b)	The structure of a chloroplast and the sites of the two main stages of photosynthesis.	To include outer membrane, lamellae, grana, thylakoid, stroma and DNA.
(c)(i)	The importance of photosynthetic pigments in photosynthesis.	To include light harvesting systems and photosystems.
(c)(ii)	Practical investigations using thin layer chromatography (TLC) to separate photosynthetic pigments.	M0.1, M0.2, M1.1, M1.3, M2.2, M2.3, M2.4 PAG6 HSW4
(d)	The light-dependent stage of photosynthesis.	To include light energy harvested to produce ATP and reduced NADP, electron carriers, cyclic and non-cyclic photophosphorylation and the role of water. HSW8
(e)	The fixation of carbon dioxide and the light-independent stage of photosynthesis.	To include Calvin cycle producing triose phosphate (TP) with RuBP, RuBisCO and GP; no other biochemical detail required. HSW8
(f)	The uses of triose phosphate (TP).	To include TP as starting material for carbohydrates, lipids and amino acids and recycling TP to regenerate RuBP.
(g)(i)	Factors affecting photosynthesis.	To include limiting factors: carbon dioxide concentration, light intensity, temperature, water stress and effects on GP, RuBP and TP.
(g)(ii)	Practical investigations into factors affecting the rate of photosynthesis.	M0.1, M0.2, M0.3, M1.1, M1.3, M1.11, M3.1, M3.2, M3.4, M3.5, M3.6, M4.1 PAG4, PAG10, PAG11 HSW3, HSW4, HSW5, HSW12

5.2.2 Respiration

Ref.	Learning outcomes	Additional guidance
(a)	The need for cellular respiration.	To include examples of why plants, animals and microorganisms need to respire, such as active transport and named metabolic reactions.
(b)	The structure of the mitochondrion.	To include inner and outer mitochondrial membranes, cristae, matrix and mitochondrial DNA.
(c)	The process and site of glycolysis.	To include phosphorylation of glucose, splitting into triose phosphate, oxidation to pyruvate and small yield of ATP and reduced NAD. HSW8
(d)	The link reaction and its site in the cell.	To include Acetyl CoA formation by pyruvate decarboxylation and NAD reduction.
(e)	The process and site of the Krebs cycle.	To include citrate formation and reconversion to oxaloacetate; decarboxylation, dehydrogenation, reduced NAD/FAD and substrate level phosphorylation. HSW8
(f)	The importance of coenzymes in cellular respiration.	With reference to NAD, FAD and coenzyme A.
(g)	The process and site of oxidative phosphorylation.	To include electron carriers, oxygen and mitochondrial cristae.
(h)	The chemiosmotic theory.	To include electron transport chain, proton gradients and ATP synthase in oxidative phosphorylation and photophosphorylation.
(i)(i)	The process of anaerobic respiration in eukaryotes.	To include anaerobic respiration in mammals and yeast, benefits, and why anaerobic respiration produces a much lower ATP yield.
(i)(ii)	Practical investigations into respiration rates in yeast, under aerobic and anaerobic conditions.	M0.1, M0.2, M1.1, M1.3, M2.4, M3.1, M3.2 PAG4, PAG10, PAG11 HSW3, HSW4
(j)	The difference in relative energy values of carbohydrates, lipids and proteins as respiratory substrates.
(k)	The use and interpretation of the respiratory quotient (RQ).	$RQ = \frac{\mathrm{CO_2\ produced}}{\mathrm{O_2\ consumed}}$ . M0.1, M0.2, M1.1, M1.3, M2.3
(l)	Practical investigations into the effect of factors such as temperature, substrate concentration and different respiratory substrates on the rate of respiration.	To include respirometers. M0.1, M0.2, M1.1, M1.2, M1.3, M1.6, M1.10, M2.4, M3.2, M3.3, M3.5, M3.6 PAG4, PAG10, PAG11 HSW3, HSW4

Module 6: Genetics, evolution and ecosystems

This module covers gene regulation, heredity, evolution, speciation, genome manipulation, biotechnology, microorganisms, cloning, ecosystems and sustainability.

6.1 Genetics and evolution

6.1.1 Cellular control

Ref.	Learning outcomes	Additional guidance
(a)	Types of gene mutations and their possible effects on protein production and function.	To include substitution, insertion or deletion of one or more nucleotides and possible beneficial, neutral or harmful effects.
(b)	The regulatory mechanisms that control gene expression at transcriptional, post-transcriptional and post-translational levels.	To include lac operon and transcription factors; editing primary mRNA and removing introns; activation of proteins by cyclic AMP. HSW2
(c)	The genetic control of the development of body plans in different organisms.	Homeobox sequences are conserved in plants, animals and fungi; Hox genes control body plan development. HSW7
(d)	The importance of mitosis and apoptosis as mechanisms controlling the development of body form.	To include genes regulating cell cycle and apoptosis responding to internal and external stimuli.

6.1.2 Patterns of inheritance

Ref.	Learning outcomes	Additional guidance
(a)(i)	The contribution of both environmental and genetic factors to phenotypic variation.	To include examples such as diet in animals and etiolation in plants.
(a)(ii)	How sexual reproduction can lead to genetic variation within a species.	Meiosis and random fusion of gametes at fertilisation.
(b)(i)	Genetic diagrams to show patterns of inheritance.	To include monogenic inheritance, dihybrid inheritance, multiple alleles, sex linkage and codominance.
(b)(ii)	The use of phenotypic ratios to identify linkage (autosomal and sex linkage) and epistasis.	To include explanations of linkage and epistasis. M0.3, M1.4 HSW2, HSW8
(c)	Using the chi-squared ( $\chi^2$ ) test to determine the significance of the difference between observed and expected results.	Formula provided: $\chi^2 = \sum \frac{(f_o - f_e)^2}{f_e}$ . M0.3, M1.4, M1.9, M2.1
(d)	The genetic basis of continuous and discontinuous variation.	To include the number of genes influencing each type of variation.
(e)	The factors that can affect the evolution of a species.	To include stabilising selection, directional selection, genetic drift, genetic bottleneck and founder effect.
(f)	The use of the Hardy-Weinberg principle to calculate allele frequencies in populations.	Equations provided where needed: $p^2 + 2pq + q^2 = 1$ and $p + q = 1$ . M0.2, M2.1, M2.2, M2.3
(g)	The role of isolating mechanisms in the evolution of new species.	To include geographical mechanisms (allopatric speciation) and reproductive mechanisms (sympatric speciation).
(h)(i)	The principles of artificial selection and its uses.	To include selective breeding in plants and animals and maintaining a genetic material resource including wild types.
(h)(ii)	The ethical considerations surrounding the use of artificial selection.	To include extreme examples of artificial selection to 'improve' domestic species e.g. dog breeds. HSW2, HSW8, HSW10, HSW12

6.1.3 Manipulating genomes

Ref.	Learning outcomes	Additional guidance
(a)	The principles of DNA sequencing and new DNA sequencing techniques.	To include advances from Sanger sequencing to high throughput sequencing. High throughput details not required. HSW7
(b)(i)	How gene sequencing has allowed for genome-wide comparisons between individuals and between species.	With reference to bioinformatics and computational biology contributing to genotype-phenotype relationships, epidemiology and evolutionary relationships.
(b)(ii)	How gene sequencing has allowed for the sequences of amino acids in polypeptides to be predicted.	PAG10 HSW7, HSW9
(b)(iii)	How gene sequencing has allowed for the development of synthetic biology.
(c)	The principles of DNA profiling and its uses.	To include forensics and analysis of disease risk. HSW9
(d)	The principles of the polymerase chain reaction (PCR) and its application in DNA analysis.
(e)	The principles and uses of electrophoresis for separating nucleic acid fragments or proteins.	Opportunity for practical use of electrophoresis. PAG6 HSW4
(f)(i)	The principles of genetic engineering.	To include isolating genes from one organism and placing them into another using suitable vectors.
(f)(ii)	The techniques used in genetic engineering.	To include restriction enzymes, plasmids and DNA ligase to form recombinant DNA and electroporation. HSW2
(g)	The ethical issues, positive and negative, relating to genetic manipulation of animals, humans, plants and microorganisms.	To include insect resistance in GM soya, GM pathogens for research, pharming, patenting and technology transfer e.g. GM seed for poor farmers. HSW10
(h)	The principles of, and potential for, gene therapy in medicine.	To include somatic cell gene therapy and germ line cell gene therapy. HSW9, HSW12

6.2 Cloning and biotechnology

6.2.1 Cloning and biotechnology

Ref.	Learning outcomes	Additional guidance
(a)(i)	Natural clones in plants and the production of natural clones for use in horticulture.	To include examples of natural cloning and vegetative propagation methods.
(a)(ii)	How to take plant cuttings as an example of a simple cloning technique.	Dissection of plant material to produce cuttings. PAG2 HSW4
(b)(i)	The production of artificial clones of plants by micropropagation and tissue culture.	To include evaluation of uses in horticulture and agriculture.
(b)(ii)	The arguments for and against artificial cloning in plants.	HSW9, HSW12
(c)	Natural clones in animal species.	To include twins formed by embryo splitting.
(d)(i)	How artificial clones in animals can be produced by artificial embryo twinning or by enucleation and somatic cell nuclear transfer (SCNT).	To include evaluation of uses in agriculture and medicine, and issues of longevity of cloned animals.
(d)(ii)	The arguments for and against artificial cloning in animals.	HSW9, HSW10, HSW12
(e)	The use of microorganisms in biotechnological processes.	To include economic considerations, short life cycle and growth requirements.
(f)	The advantages and disadvantages of using microorganisms to make food for human consumption.	To include bacterial and fungal sources. HSW9, HSW12
(g)(i)	How to culture microorganisms effectively, using aseptic techniques.	Opportunity for serial dilutions and culturing on agar plates. PAG7 HSW4
(g)(ii)	The importance of manipulating growing conditions in batch and continuous fermentation to maximise product yield.
(h)(i)	The standard growth curve of a microorganism in a closed culture.	To include formula for number of individual organisms: $N = N_0 \times 2^n$ .
(h)(ii)	Practical investigations into the factors affecting the growth of microorganisms.	Opportunity for serial dilutions and broth. M0.1, M0.3, M0.5, M1.1, M1.3, M2.5, M3.1, M3.2, M3.4, M3.5, M3.6 PAG7 HSW4
(i)	The uses of immobilised enzymes in biotechnology and the different methods of immobilisation.	To include immobilisation methods and evaluation of uses; examples could include glucose isomerase, penicillin acylase, lactase, aminoacylase and glucoamylase. Learners need not recall examples but should apply knowledge. M0.2, M0.3, M1.2, M1.3, M1.4, M1.6, M1.10, M3.2, M4.1 PAG4 HSW4

6.3 Ecosystems

6.3.1 Ecosystems

Ref.	Learning outcomes	Additional guidance
(a)	Ecosystems, which range in size, are dynamic and are influenced by both biotic and abiotic factors.	To include ecosystems of different sizes and named examples of biotic and abiotic factors.
(b)	Biomass transfers through ecosystems.	To include measuring biomass transfers, efficiency between trophic levels and human manipulation of biomass transfer. $\text{efficiency} = \frac{\text{biomass transferred}}{\text{biomass intake}} \times 100$ . M0.1, M0.2, M0.3, M0.4, M1.1, M1.3, M1.6 HSW12
(c)	Recycling within ecosystems.	To include decomposers, microorganisms in nitrogen recycling (Nitrosomonas, Nitrobacter, Azotobacter, Rhizobium) and the carbon cycle including decomposition, respiration and photosynthesis plus physical and chemical effects. HSW2, HSW12
(d)	The process of primary succession in the development of an ecosystem.	To include succession from pioneer species to climax community and deflected succession. HSW12
(e)(i)	How the distribution and abundance of organisms in an ecosystem can be measured.	M1.3, M1.4, M1.5, M1.7, M1.9, M1.10, M3.1, M3.2 PAG3 HSW4
(e)(ii)	The use of sampling and recording methods to determine distribution and abundance in a variety of ecosystems.

6.3.2 Populations and sustainability

Ref.	Learning outcomes	Additional guidance
(a)	The factors that determine size of a population.	To include limiting factors, carrying capacity and impact on final population size. M0.1, M0.2, M0.3, M0.4, M0.5, M1.3, M2.5, M3.1, M3.2 HSW1, HSW2
(b)	Interactions between populations.	To include predator-prey relationships and interspecific/intraspecific competition.
(c)	The reasons for, and differences between, conservation and preservation.	To include economic, social and ethical reasons for conservation of biological resources. HSW7, HSW9, HSW10, HSW12
(d)	How the management of an ecosystem can provide resources in a sustainable way.	Limited to management of ecosystems for timber production and fishing. HSW12
(e)	The management of environmental resources and the effects of human activities.	To include balancing conservation/preservation with human needs and the effects of human activities on animal and plant populations and how these are controlled. HSW7, HSW12