A LEVEL

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A LEVEL : GCE AS and A level subject content for biology, chemistry, physics and psychology

Introduction

1. AS and A level subject content sets out the knowledge, understanding and skills common to all AS and A level specifications in biology, chemistry, physics and psychology. Aims and objectives
2. AS and A level specifications in a science subject must encourage students to:
• develop essential knowledge and understanding of different areas of the subject and how they relate to each other
• develop and demonstrate a deep appreciation of the skills, knowledge and understanding of scientific methods
• develop competence and confidence in a variety of practical, mathematical and problem solving skills
• develop their interest in and enthusiasm for the subject, including developing an interest in further study and careers associated with the subject
• understand how society makes decisions about scientific issues and how the sciences contribute to the success of the economy and society Subject content
3. AS and A level science specifications must build on the skills, knowledge and understanding set out in the GCSE criteria/content for science.
4. The skills, knowledge and understanding set out in the appendices for AS in each science subject must comprise approximately 60 per cent of AS specifications. The skills,
knowledge and understanding for A level must comprise approximately 60 per cent of an A level specification. For A level this would include all the practical requirements in Appendix 5, while for AS it would include those from Appendix 5a. For both AS and A level it would include the mathematical requirements on Appendix 6.
5. The remainder of both AS and A level specifications allows both for:
• further consideration of applications and implications of science and the development of scientific ideas 3
• the introduction of different areas of study
6. AS and A level specifications must include a range of contemporary and other contexts.
7. AS and A level specifications must require students to cover the areas of the subject as illustrated in the relevant appendix.
8. The skills, knowledge and understanding of each specification in the subject must, where appropriate, include the requirements set out below, and be integrated into the mandatory content indicated in the relevant appendix and any content added by the awarding organisation, where appropriate:
• use theories, models and ideas to develop scientific explanations
• use knowledge and understanding to pose scientific questions, define scientific problems, present scientific arguments and scientific ideas
• use appropriate methodology, including information and communication technology (ICT), to answer scientific questions and solve scientific problems
• carry out experimental and investigative activities, including appropriate risk management, in a range of contexts
• analyse and interpret data to provide evidence, recognising correlations and causal relationships
• evaluate methodology, evidence and data, and resolve conflicting evidence
• know that scientific knowledge and understanding develops over time
• communicate information and ideas in appropriate ways using appropriate terminology
• consider applications and implications of science and evaluate their associated benefits and risks
• consider ethical issues in the treatment of humans, other organisms and the environment
• evaluate the role of the scientific community in validating new knowledge and ensuring integrity
• evaluate the ways in which society uses science to inform decision making1. AS and A level subject content sets out the knowledge, understanding and skills common to all AS and A level specifications in biology, chemistry, physics and psychology. Aims and objectives

A LEVEL BIOLOGY

The A level knowledge and understanding combined must comprise approximately 60 per cent of an A level specification. All of the content below is required for the A level.
The AS knowledge and understanding set out in this appendix must comprise approximately 60 per cent of the AS specification, and is shown below in normal (nonbold) text.
1. Biology specifications must ensure that there is an appropriate balance between plant biology, animal biology and microbiology and include an appreciation of the relevance of sustainability to all aspects of scientific developments.
2. Living organisms, including plants, animals and microorganisms, interact with each other and with the non-living world. The living world can be studied at population, organism, cell and molecular levels. There are fundamental similarities as well as differences between plants, animals and microorganisms.
3. Biodiversity
• the variety of life, both past and present, is extensive, but the biochemical basis of life is similar for all living things
• biodiversity refers to the variety and complexity of life and may be considered at different levels
• biodiversity can be measured, for example within a habitat or at the genetic level
• classification is a means of organising the variety of life based on relationships between organisms and is built around the concept of species
• originally classification systems were based on observable features but more recent approaches draw on a wider range of evidence to clarify relationships between organisms
• adaptations of organisms to their environments can be behavioural, physiological and anatomical
• adaptation and selection are major factors in evolution and make a significant contribution to the diversity of living organisms
4. Exchange and transport
• organisms need to exchange substances selectively with their environment and this takes place at exchange surfaces
• factors such as size or metabolic rate affect the requirements of organisms and this gives rise to adaptations such as specialised exchange surfaces and mass transport systems
• substances are exchanged by passive or active transport across exchange surfaces
• the structure of the plasma membrane enables control of the passage of substances into and out of cells
5. Cells
• the cell theory is a unifying concept in biology
• prokaryotic and eukaryotic cells can be distinguished on the basis of their structure and ultrastructure
• in complex multicellular organisms cells are organised into tissues, tissues into organs and organs into systems
• during the cell cycle genetic information is copied and passed to daughter cells
• daughter cells formed during mitosis have identical copies of genes while cells formed during meiosis are not genetically identical
6. Biological molecules
• biological molecules are often polymers and are based on a small number of chemical elements
• in living organisms nucleic acids (DNA and RNA), carbohydrates, proteins, lipids,
inorganic ions and water all have important roles and functions related to their properties
• the sequence of bases in the DNA molecule determines the structure of proteins, including enzymes
• enzymes catalyse the reactions that determine structures and functions from cellular to whole-organism level
• enzymes are proteins with a mechanism of action and other properties determined by their tertiary structure
• enzymes catalyse a wide range of intracellular reactions as well as extracellular ones
• ATP provides the immediate source of energy for biological processes
7. Ecosystems
• ecosystems range in size from the very large to the very small
• biomass transfers through ecosystems and the efficiency of transfer through different trophic levels can be measured
• microorganisms play a key role in recycling chemical elements
• ecosystems are dynamic systems, usually moving from colonisation to climax communities in a process known as succession
• the dynamic equilibrium of populations is affected by a range of factors
• humans are part of the ecological balance and their activities affect it both directly and indirectly
• effective management of the conflict between human needs and conservation help to maintain sustainability of resources
8. Control systems
• homeostasis is the maintenance of a constant internal environment
• negative feedback helps maintain an optimal internal state in the context of a
dynamic equilibrium. Positive feedback also occurs
• stimuli, both internal and external, are detected leading to responses
• the genome is regulated by a number of factors
• coordination may be chemical or electrical in nature
9. Genetics and evolution
• transfer of genetic information from one generation to the next can ensure continuity of species or lead to variation within a species and possible formation of new species
• reproductive isolation can lead to accumulation of different genetic information in populations potentially leading to formation of new species
• sequencing projects have read the genomes of organisms ranging from microbes and plants to humans. This allows the sequences of the proteins that derive from the genetic code to be predicted
• gene technologies allow study and alteration of gene function in order to better understand organism function and to design new industrial and medical processes
10. Energy for biological processes
• in cellular respiration, glycolysis takes place in the cytoplasm and the remaining steps in the mitochondria
• ATP synthesis is associated with the electron transfer chain in the membranes of mitochondria and chloroplasts
• in photosynthesis energy is transferred to ATP in the light- dependent stage and the ATP is utilised during synthesis in the light-independent stage

A LEVEL CHEMISTRY

1. Chemistry specifications must ensure that there is an appreciation of the relevance of sustainability to all aspects of scientific developments.
2. Formulae, equations and amounts of substance
• empirical and molecular formulae
• balanced chemical equations (full and ionic)
• the Avogadro constant and the amount of substance (mole)
• relative atomic mass and relative isotopic mass
• calculation of reacting masses, mole concentrations, volumes of gases, per cent yields and atom economies
• simple acid–base titrations
• non-structured titration calculations, based solely on experimental results
3. Atomic structure
• structure and electronic configuration of atoms (up to Z = 36) in terms of main energy levels and s, p and d orbitals
• ions and isotopes; use of mass spectrometry in determining relative atomic mass and relative abundance of isotopes
4. Bonding and structure
• interpretation of ionic and covalent bonding in terms of electron arrangements. Examples of simple covalent, giant covalent, ionic and metallic structures
• permanent and induced dipole–dipole interactions between molecules, including hydrogen bonding. Electronegativity and its application to bond type. Interpretation of the physical properties of materials in terms of structure and bonding
• shapes of simple molecules and ions with up to six outer pairs of electrons (any combination of bonding pairs and lone pairs). Interpretation in terms of electron pair repulsion theory
5. Energetics • enthalpy changes, including standard enthalpy changes of reaction, formation and combustion. Average bond enthalpies
• use of Hess’s law to calculate enthalpy changes
• use of energetics, including entropy, to predict the feasibility of reactions
6. Kinetics
• a qualitative understanding of collision theory. Activation energy and its relationship to the qualitative effect of temperature changes on rate of reaction. Boltzman distribution
• the role of catalysts in providing alternative routes of lower activation energy
• determination and use of rate equations of the form: Rate = k[A]m[B]n, where m and n are integers. Using orders of reactions where appropriate, which may give information about a rate-determining/limiting step
7. Equilibria
• the dynamic nature of equilibria. For homogeneous reactions, the qualitative effects of temperature, pressure and concentration changes on the position of equilibrium
• equilibrium constants, Kc
• calculation of Kc and reacting quantities
• the effect of temperature changes on Kc
• the Bronsted–Lowry theory of acid–base reactions. The ionic product of water, Kw; pH and its calculation for strong acids and strong bases
• dissociation constants of weak acids, Ka. Calculation of pH for weak acids. Buffer solutions and their applications
8. Redox
• oxidation states and their calculation
• oxidation and reduction as electron transfer, applied to reactions of s, p and d block elements
• electrode potentials and their applications
9. Inorganic chemistry and the periodic table
• the organisation of elements according to their proton number and electronic structures. Classification of elements into s, p and d blocks
• the characteristic reactions of the elements and compounds of a metallic group and a non-metallic group. Trends in properties of elements and compounds within these groups
• trends in properties of elements across a period including:
• melting point
• ionisation energy
• the transition metals as d block elements forming one or more stable ions that have incompletely filled d orbitals. At least two transition metals, chosen from titanium to copper, to illustrate:
• the existence of more than one oxidation state for each element in its compounds
• the formation of coloured ions in solution and simple precipitation reactions of these
• reactions with ligands to form complexes and reactions involving ligand substitution
• the catalytic behaviour of the elements and their compounds
10. Organic chemistry
• functional groups. Structural isomers and stereoisomers (to include geometric (E–Z) isomerism as a result of restricted rotation about a carbon–carbon double bond and optical isomerism as a result of chirality in molecules with a single chiral centre)
• reactions classified as addition, elimination, substitution, oxidation, reduction, hydrolysis, addition polymerisation and condensation polymerisation
• mechanisms classified as radical substitution, electrophilic addition, nucleophilic substitution, electrophilic substitution and nucleophilic addition
• single and double covalent bonds, bond polarity and bond enthalpy as factors influencing reactivity, illustrated by reference to appropriate reactions
• the structure of, and the bonding in, benzene
• organic synthesis, including characteristic reactions of alkanes, alkenes, halogenoalkanes, alcohols, arenes, aldehydes, ketones, carboxylic acids, esters, amines, amino acids and amides
11. Modern analytical techniques
• the use of mass spectrometry, infrared spectroscopy, nuclear magnetic resonance spectroscopy and chromatography in analysis, including techniques for the elucidation of structure1. Chemistry specifications must ensure that there is an appreciation of the relevance of sustainability to all aspects of scientific developments.

A LEVEL PHYSICS

All physics specifications must ensure that there is an appropriate balance between mathematical calculations and written explanations. They also need to ensure that practical skills are developed.
1. All physics specifications must require knowledge and understanding of:
• the use of SI units and their prefixes
• Newton’s laws of motion
• the estimation of physical quantities
• the limitations of physical measurements
2. Vectors and scalars
• the distinction between vector and scalar quantities
• resolution of vectors into two components at right angles
• addition rule for two vectors
• calculations for two perpendicular vectors
3. Mechanics
• kinematics:
• use of kinematic equations in one dimension with constant velocity or acceleration
• graphical representation of accelerated motion
• interpretation of velocity-time and displacement-time graphs
• dynamics:
• use of F = ma when mass is constant
• one- and two-dimensional motion under constant force
• independent effect of perpendicular components with uniform acceleration, projectile motion
• energy:
• calculation of work done for constant forces, including force not along the line of motion
• calculation of exchanges between gravitational potential energy and kinetic energy
• principle of conservation of energy
• momentum:
• definition
• principle of conservation of momentum
• calculations for one-dimensional problems
• circular motion:
• radian measure of angle and angular velocity
• application of F = ma = mv2/r = mrω2 to motion in a circle at constant speed
• oscillations:
• simple harmonic motion
• quantitative treatment using a = –ω²x and its solution x = A cos ωt.
4. Mechanical properties of matter
• stress, strain, Young modulus
• force-extension graphs, energy stored
5. Electric circuits
• current:
• electric current as rate of flow of charge, I = Δq/Δt
• emf and potential difference:
• definition of emf and concept of internal resistance
• potential difference in terms of energy transfer
• resistance:
• definition
• resistivity
• Ohm’s law
• DC Circuits:
• conservation of charge and energy in circuits
• relationships between currents, voltages and resistances in series and parallel circuits
• power dissipated
• potential divider circuits
• capacitance:
• definition
• energy of a capacitor
• quantitative treatment of charge and discharge curves
6. Waves
• qualitative treatment of polarisation and diffraction
• path difference, phase and coherence, interference
• graphical treatment of superposition and stationary waves
7. Matter
• molecular kinetic theory:
• ideal gases; pV = NkT
• absolute zero
• relationship between temperature and average molecular
kinetic energy
• internal energy:
• idea of internal energy
• energy required for temperature change = mcΔθ
8. Quantum and nuclear physics
• photons and particles:
• photon model to explain observable phenomena
• evidence supporting the photon model
• wave-particle duality, particle diffraction
• nuclear decay:
• connections between nature, penetration and range of emissions from
radioactive substances • evidence for existence of nucleus
• activity of radioactive sources and idea of half-life
• modelling with constant decay probability leading to exponential decay
• nuclear changes in decay
• nuclear energy:
• fission and fusion processes
• E = mc2 applied to nuclear processes
• calculations relating mass difference to energy change

9. Fields
• force fields:
• concept and definition
• gravitational force and inverse square field for point (or spherical) masses
• electric force and field for point (or spherical) charges in a vacuum
• electric and gravitational potential and changes in potential energy
• uniform electric field
• similarities and differences between electric and gravitational fields
• B-fields:
• force on a straight wire and force on a moving charge in a uniform field
• flux and electromagnetic induction:
• concept and definition
• Faraday’s and Lenz’s laws
• emf equals the rate of change of magnetic flux linkage

A LEVEL MATHS

1. A level mathematics provides a framework within which a large number of young people continue the subject beyond GCSE level. It supports their mathematical needs across a broad range of other subjects at this level and provides a basis for subsequent quantitative work in a very wide range of higher education courses and in employment. It also supports the study of AS and A level further mathematics.
2. A level mathematics builds from GCSE level mathematics and introduces calculus and its applications. It emphasises how mathematical ideas are interconnected and how mathematics can be applied to model situations mathematically using algebra and other representations, to help make sense of data, to understand the physical world and to solve problems in a variety of contexts, including social sciences and business. It prepares students for further study and employment in a wide range of disciplines involving the use of mathematics.
3. AS mathematics, which can be co-taught with the A level as a separate qualification, is a very useful qualification in its own right. It consolidates and develops GCSE level mathematics and supports transition to higher education or employment in any of the many disciplines that make use of quantitative analysis, including those involving calculus.

Aims and Objectives

1. AS and A level specifications in mathematics must encourage students to:
• understand mathematics and mathematical processes in a way that promotes confidence, fosters enjoyment and provides a strong foundation for progress to further study
• extend their range of mathematical skills and techniques
• understand coherence and progression in mathematics and how different areas of mathematics are connected
• apply mathematics in other fields of study and be aware of the relevance of mathematics to the world of work and to situations in society in general
2
• use their mathematical knowledge to make logical and reasoned decisions in solving problems both within pure mathematics and in a variety of contexts, and communicate the mathematical rationale for these decisions clearly
• reason logically and recognise incorrect reasoning
• generalise mathematically
• construct mathematical proofs
• use their mathematical skills and techniques to solve challenging problems which require them to decide on the solution strategy
• recognise when mathematics can be used to analyse and solve a problem in context
• represent situations mathematically and understand the relationship between problems in context and mathematical models that may be applied to solve them
• draw diagrams and sketch graphs to help explore mathematical situations and interpret solutions
• make deductions and inferences and draw conclusions by using mathematical reasoning
• interpret solutions and communicate their interpretation effectively in the context of the problem
• read and comprehend mathematical arguments, including justifications of methods and formulae, and communicate their understanding
• read and comprehend articles concerning applications of mathematics and communicate their understanding
• use technology such as calculators and computers effectively and recognise when such use may be inappropriate
• take increasing responsibility for their own learning and the evaluation of their own mathematical development