# GCE O Level Syllabus

**GCE O Level Syllabus Overview**

When preparing for an important paper such as the O Level examination, it is important to understand not only the topics in the subject, but also the details of the paper. Over here, we have compiled a detailed list of what a student can expect to be tested on for O Level subjects. Remember, it is never too late to start preparing! All information below was taken from the SEAB website.

Learn more about each O Level subject:

**Note: The O Level syllabus will change from 2023 onwards. The information below is based on the examination syllabus offered to school candidates up until 2022. Information on the new syllabus will be updated after the 2022 O Level examination.*

**English**

In this English Language examination, candidates will be assessed on their ability to:

- speak and write in internationally acceptable English
- respond, in speech or writing, to a variety of written, spoken and visual texts
- speak, read aloud and write to suit purpose, audience and context
- speak and write using appropriate register and tone
- speak and write clearly, effectively, relevantly and coherently
- plan, organise and show development of ideas
- use varied sentence structures and a wide and appropriate vocabulary with clarity and precision
- use correct grammar, punctuation and spelling
- show understanding of a variety of written, spoken and visual texts at the literal, inferential and evaluative levels
- show understanding of how use of language achieves purpose and impact
- identify main ideas and details in written, spoken and visual texts
- synthesise, summarise and organise information
- read aloud a given text with accurate pronunciation and clear articulation
- read aloud a given text fluently with appropriate variations in voice qualities, i.e. pace, volume, tone and stress.

**Elementary Mathematics**

The O Level Mathematics syllabus is intended to provide students with fundamental mathematical knowledge and skills. The content is organised into three strands:

- Number and Algebra
- Geometry and Measurement
- Statistics and Probability

When preparing for a critical examination, students must understand and revise all the topics in a subject. Over here, we have compiled a list of all the topics tested in the subject and what to expect in the papers.

**SECTION I: NUMBERS AND ALGEBRA**

**Numbers and their operations**

- primes and prime factorisation
- finding highest common factor (HCF) and lowest common multiple (LCM), squares, cubes, square roots and cube roots by prime factorisation
- negative numbers, integers, rational numbers, real numbers, and their four operations
- calculations with calculator
- representation and ordering of numbers on the number line
- use of the symbols <, >, ⩽, ⩾
- approximation and estimation (including rounding off numbers to a required number of decimal places or significant figures and estimating the results of computation)
- use of standard form \(A = 10^n\), where \(n\) is an integer, and 1 ⩽ \(A\) < 10
- positive, negative, zero and fractional indices
- laws of indices

**Ratio and proportion**

- ratios involving rational numbers
- writing a ratio in its simplest form
- map scales (distance and area)
- direct and inverse proportion

**Percentage**

- expressing one quantity as a percentage of another
- comparing two quantities by percentage
- percentages greater than 100%
- increasing/decreasing a quantity by a given percentage
- reverse percentages

**Rate and speed**

- average rate, speed, constant speed and average speed
- conversion of units (e.g. km/h to m/s)

**Algebraic expressions and formulae**

- using letters to represent numbers
- interpreting notations
- evaluation of algebraic expressions and formulae
- translation of simple real-world situations into algebraic expressions
- recognising and representing patterns/relationships by finding an algebraic expression for the nth term
- addition and subtraction of linear expressions
- simplification of linear expression such as

\(-2(3x-5) +4x\)

\({2x\over 3} - {3(x-5)\over 2}\) - use of brackets and extract common factors
- expansion of the product of algebraic expressions
- changing the subject of a formula
- finding the value of an unknown quantity in a given formula
- use of

(i) \((a+b)^2 = a^2 + 2ab + b^2\)

(ii) \((a-b)^2 = a^2 - 2ab + b^2\)

(iii) \(a^2-b^2 =(a+b)(a-b)\) - factorisation of quadratic expressions \(ax^2+bx+c\)
- multiplication and division of simple algebraic fractions
- addition and subtraction of algebraic fractions with linear or quadratic denominator such as \({1 \over x-2} +{2 \over x-3}\)

**Functions and Graphs**

- Cartesian coordinates in two dimensions
- graph of a set of ordered pairs as a representation of a relationship between two variables
- linear functions and and quadratic functions
- graphs of linear functions
- the gradient of a linear graph as the ratio of the vertical change to the horizontal change (positive and negative gradients)
- graphs of quadratic functions and their properties

(i) positive or negative coefficient of \(x^2\)

(ii) maximum and minimum points

(iii) symmetry - sketching the graphs of quadratic functions in the form: \(y = (x-p)^2 +q\)

(ii)\(y = (x-p)^2 +q\)

(iii) \(y = (x-p)^2 +q\)

(iv) \(y = (x-p)^2 +q\) - graphs of power functions of the form \(y = ax^n\) , where \(n = -2, -1, 0, 1, 2, 3\) and simple sums of not more than three of these
- graphs of exponential functions \(y = ka^x\) , where a is a positive integer estimation of the gradient of a curve by drawing a tangent

**Equations and Inequalities**

- solving linear equations in one variable
- solving simple fractional equations that can be reduced to linear equations
- solve inequalities in the form of \(ax+bc\)
- graphs of linear equations in two variables \((ax+b-c)\)
- solving simultaneous linear equations in two variables by

(i) substitution and elimination methods

(ii) graphical method - solving quadratic equations in one unknown by

(i) factorisation

(ii) use of formula

(iii) completing the square

(iv) graphical methods - solving fractional equations that can be reduced to quadratic equations
- formulating equations to solve problems
- solving linear inequalities in one variable (including simultaneous inequalities), and representing the solution on the number line

**Set Language and Notation**

- use of set language
- union and intersection of two sets
- Venn diagrams

**Matrices**

- display of information in the form of a matrix of any order
- interpreting the data in a given matrix
- product of a scalar quantity and a matrix
- problems involving addition, subtraction and multiplication of matrices

**SECTION II: GEOMETRY AND MEASUREMENT**

**Angles, triangles and polygons**

- right, acute, obtuse and reflex angles
- vertically opposite angles, angles on a straight line and angles at a point x
- angles formed by two parallel lines and a transversal: corresponding angles, alternate angles, interior angles properties of triangles, special quadrilaterals and regular polygons (pentagon, hexagon, octagon and decagon), including symmetry properties
- classifying special quadrilaterals on the basis of their properties
- angle sum of interior and exterior angles of any convex polygon
- construction of simple geometrical figures from given data (including perpendicular bisectors and angle bisectors) using compasses, ruler, set squares and protractors, where appropriate

**Congruence and similarity**

- congruent figures
- similar figures
- properties of similar triangles and polygons
- enlargement and reduction of a plane figure
- scale drawings
- properties and construction of perpendicular bisectors of line segments and angle bisectors
- determining whether two triangles are congruent or similar
- ratio of areas of similar plane figures
- ratio of volumes of similar solids

**Properties of Circles**

- symmetry properties of circles:

(i) equal chords are equidistant from the centre

(ii) the perpendicular bisector of a chord passes through the centre

(iii) tangents from an external point are equal in length

(iv) the line joining an external point to the centre of the circle bisects the angle between the tangents - angle properties of circles:

(i) angle in a semicircle is a right angle

(ii) angle between tangent and radius of a circle is a right angle

(iii) angle at the centre is twice the angle at the circumference

(iv) angles in the same segment are equal

(v) angles in opposite segments are supplementary

**Pythagoras’ theorem and trigonometry**

- use of Pythagoras’ theorem
- determining whether a triangle is right-angled given the lengths of three sides
- use of trigonometric ratios (sine, cosine and tangent) of acute angles to calculate unknown sides and angles in right-angled triangles
- extending sine and cosine to obtuse angles
- use of the formula of \({1\over2}ab\sin C\) for the area of a triangle
- use of sine rule and cosine rule for any triangle
- problems in two and three dimensions including those involving angles of elevation and depression and bearings

**Mensuration**

- area of parallelogram and trapezium
- problems involving perimeter and area of composite plane figures
- volume and surface area of cube, cuboid, prism, cylinder, pyramid, cone and sphere
- conversion between cm\(^2\) and m\(^2\) , and between cm\(^3\) and m\(^3\)
- problems involving volume and surface area of composite solids
- arc length, sector area and area of a segment of a circle
- use of radian measure of angle (including conversion between radians and degrees)

**Coordinate geometry**

- finding the gradient of a straight line given the coordinates of two points on it
- finding the length of a line segment given the coordinates of its end points
- interpreting and finding the equation of a straight line graph in the form y=mx+c
- geometric problems involving the use of coordinates

**Vectors in two dimensions**

- use of vector notations
- representing a vector as a directed line segment
- translation by a vector
- position vectors
- magnitude of a vector
- use of sum and difference of two vectors to express given vectors in terms of two coplanar vectors
- multiplication of a vector by a scalar
- geometric problems involving the use of vectors

**SECTION III: STATISTICS AND PROBABILITY**

**Data Analysis**

- analysis and interpretation of:

(i) tables

(ii) bar graphs

(iii) pictograms

(iv) line graphs

(v) pie charts

(vi) dot diagrams

(vii) histograms with equal class intervals

(viii) stem-and-leaf diagrams

(ix) cumulative frequency diagrams

(x) box-and-whisker plots - purposes and uses, advantages and disadvantages of the different forms of statistical representations
- explaining why a given statistical diagram leads to misinterpretation of data
- mean, mode and median as measures of central tendency for a set of data
- purposes and use of mean, mode and median
- calculation of the mean for grouped data
- quartiles and percentiles
- range, interquartile range and standard deviation as measures of spread for a set of data
- calculation of the standard deviation for a set of data (grouped and ungrouped)
- using the mean and standard deviation to compare two sets of data

**Probability**

- probability as a measure of chance
- probability of single events (including listing all the possible outcomes in a simple chance situation to calculate the probability)
- probability of simple combined events (including using possibility diagrams and tree diagrams, where appropriate)
- addition and multiplication of probabilities (mutually exclusive events and independent events)

** Additional Mathematics**

The O Level Additional Mathematics syllabus is intended to provide students with fundamental mathematical knowledge for A-Level H2 Mathematics. The content is organised into three strands:

- Algebra
- Geometry and Trigonometry
- Calculus

When preparing for a critical examination, students must understand and revise all the topics in a subject. Over here, we have compiled a list of all the topics tested in the subject and what to expect in the papers.

**SECTION I: ALGEBRA**

**Quadratic functions**

- Finding the maximum or minimum value of a quadratic function using the method of completing the square
- Conditions for \(y=ax^2+bx+c\) to be always positive (or always negative)
- Using quadratic functions as modelsprimes and prime factorisation

**Equations and inequalities**

- Conditions for a quadratic equation to have:
- (i) two real roots, (ii) two equal roots, (iii) no real roots

and related conditions for a given line to: - (i) intersect a given curve, (ii) be a tangent to a given curve, (iii) not intersect a given curve

- (i) two real roots, (ii) two equal roots, (iii) no real roots
- Solving simultaneous equations in two variables by substitution, with one of the equations being a linear equation
- Solving quadratic inequalities, and representing the solution on the number lineratios involving rational numbers

**Surds**

- Four operations on surds, including rationalising the denominator
- Solving equations involving surds

**Polynomials and partial fractions**

- Multiplication and division of polynomials
- Use of remainder and factor theorems, including factorising polynomials and solving cubic equations
- Use of:
- \(a^3+b^3=(a+b)(a^2-ab+b^2)\)
- \(a^3-b^3=(a-b)(a^2+ab+b^2)\)

- Partial fractions with cases where the denominator is no more complicated than:
- \((ax+b)(cx+d)\)
- \((ax+b)(cx+d)^2\)
- \((ax+b)(x^2+c^2)\)

**Binomial expansions**

- Use of the Binomial Theorem for positive integer n
- Use of the notations \(n!\) and \(\binom{n}{r}\)
- Use of the general term \(\binom{n}{r}a^{n-r}b^r, 0\le r \le n\) (knowledge of the greatest term and properties of the coefficients is not required)

**Exponential and logarithmic functions**

- Exponential and logarithmic functions \(a^x\) , \(e^x\) , \(log_{a}x\), \(\ln x\) and their graphs, including:
- laws of logarithms
- equivalence of \(y=a^x\)and \(x=\log_{a}y\)
- change of base of logarithms

- Simplifying expressions and solving simple equations involving exponential and logarithmic functions
- Using exponential and logarithmic functions as models

**SECTION II: GEOMETRY AND TRIGONOMETRY**

**Trigonometric functions, identities and equations**

- Six trigonometric functions for angles of any magnitude (in degrees or radians)
- Principal values of \(\sin^{-1}x, \cos^{-1}x, \tan^{-1}x\)
- Exact values of the trigonometric functions for special angles \((30^\circ, 45^\circ, 60^\circ)\) or \((\frac{\pi}{6},\frac{\pi}{4},\frac{\pi}{3})\)
- Amplitude, periodicity and symmetries related to sine and cosine functions
- Graphs of \(y=a \sin(bx)+c, y=a \sin(\frac{x}{b})+c, y=a \cos(bx)+c, y=a \cos(\frac{x}{b})+c, y=a \tan(bx)\) where \(a\) is real, \(b\) is a positive integer and \(c\) is an integer
- Use of:

\(\frac{\sin A}{\cos A}=\tan A, \frac{\cos A}{\sin A}=\cot A, \sin^2A+cos^2A=1 \\\\ \sec^2A=1+\tan^2A, \DeclareMathOperator{cosec}{cosec} \cosec^2A=1+\cot^2A\) - the expressions of \(\sin(A\pm B), \cos(A\pm B), \tan(A \pm B)\)
- the formulae for \(\sin2A, \cos2A, \tan2A\)
- the expression of \(a\cos\theta+b\sin\theta\) in the form \(R\cos(\theta\pm\alpha) \text{ or } R\sin(\theta\pm\alpha)\)
- Simplification of trigonometric expressions
- Solution of simple trigonometric equations in a given interval (excluding general solution)
- Proofs of simple trigonometric identities
- Using trigonometric functions as models

**Coordinate geometry in two dimensions**

- Condition for two lines to be parallel or perpendicular
- Midpoint of line segment
- Area of rectilinear figure
- Coordinate geometry of circles in the form:

\((x-a)^2+(y-b)^2=r^2\)

\(x^2+y^2+2gx+2fy+c=0\)

(excluding problems involving two circles) - Transformation of given relationships, including \(y=ax^n\) = and \(y=kb^x\), to linear form to determine the unknown constants from a straight line graph

**Proofs in Plane Geometry**

- Use of:
- properties of parallel lines cut by a transversal, perpendicular and angle bisectors, triangles, special quadrilaterals and circles
- congruent and similar triangles
- midpoint theorem
- tangent-chord theorem (alternate segment theorem)

**SECTION III: CALCULUS**

**Differentiation and Integration**

- Derivative of \(f(x)\) as the gradient of the tangent to the graph of \(y=f(x)\) at a point
- Derivative as rate of change
- Use of standard notations
- \(f'(x), f''(x), \frac{dy}{dx}, \frac{d^2y}{dx^2}[=\frac{d}{dx}(\frac{dy}{dx})]\)

- Derivatives of \(x^n\) , for any rational \(n\), \(\sin x, \cos x, \tan x, e^x, \ln x\), together with constant multiples, sums and differences
- Derivatives of products and quotients of functions
- Use of Chain Rule
- Increasing and decreasing functions
- Stationary points (maximum and minimum turning points and stationary points of inflexion)
- Use of second derivative test to discriminate between maxima and minima
- Apply differentiation to gradients, tangents and normals, connected rates of change and maxima and minima problems
- Integration as the reverse of differentiation
- Integration of n x for any rational \(n, \sin x, \cos x, \sec^2x, e^x\) together with constant multiples, sums and differences
- Integration of \((ax+b)^n\) + for any rational \(n\), \(\sin(ax+b), \cos(ax+b)\) and \(e^{ax+b}\)
- Definite integral as area under a curve
- Evaluation of definite integrals
- Finding the area of a region bounded by a curve and line(s) (excluding area of region between 2 curves)
- Finding areas of regions below the x-axis
- Application of differentiation and integration to problems involving displacement, velocity and acceleration of a particle moving in a straight line

Physics

Physics

*Note: The O Level Physics syllabus will change from 2023 onwards. The information below is based on the examination syllabus offered to school candidates up until 2022. Information on the new syllabus will be updated after the 2022 O Level examination.*

**SECTION I: MEASUREMENT**

In this section, students will examine how a set of base physical quantities and units is used to describe all other physical quantities. These precisely defined quantities and units, with accompanying order-of-ten prefixes (e.g. milli, centi and kilo) can then be used to describe the interactions between objects in systems that range from celestial objects in space to sub-atomic particles.

**Physical quantities and measurement**

*Sub topics covered: Physical quantities, SI units, Prefixes, Scalars and Vectors, Measurement of length and time*

- show understanding that all physical quantities consist of a numerical magnitude and a unit
- recall the following base quantities and their units: mass (kg), length (m), time (s), current (A), temperature (K)
- use the following prefixes and their symbols to indicate decimal sub-multiples and multiples of the SI units: nano (n), micro (μ), milli (m), centi (c), deci (d), kilo (k), mega (M), giga (G) how an understanding of the orders of magnitude of the sizes of common objects ranging from a typical atom to the Earth
- state what is meant by scalar and vector quantities and give common examples of each
- add two vectors to determine a resultant by a graphical method
- describe how to measure a variety of lengths with appropriate accuracy by means of tapes, rules, micrometers and calipers, using a vernier scale as necessary

**SECTION II: NEWTONIAN MECHANICS**

When talking about mechanics, one might picture a car or even a garage shop. In Physics, Mechanics is the branch that deals with the study of motion and its causes. In this section, students will begin understanding the topic by examining kinematics, which is a study of motion without regard for the cause. After which, students will study the conditions required for an object to be accelerated and introduce the concept of forces through Newton’s Laws. The section finally rounds up by reading the discussion from force to work and energy, and the use of the principle of conservation of energy to explain interactions between bodies.

**Kinematics**

*Sub topics covered: Speed, velocity and acceleration, Graphical analysis of motion, Free fall*

- state what is meant by speed and velocity
- calculate average speed using distance travelled / time taken
- state what is meant by uniform acceleration and calculate the value of an acceleration using change in velocity / time taken
- interpret given examples of non-uniform acceleration
- plot and interpret a distance-time graph and a speed-time graph
- deduce from the shape of a distance-time graph when a body is:

(i) at rest

(ii) moving with uniform speed

(iii) moving with non-uniform speed - deduce from the shape of a speed-time graph when a body is:

(i) at rest

(ii) moving with uniform speed

(iii) moving with uniform acceleration

(iv) moving with non-uniform acceleration - calculate the area under a speed-time graph to determine the distance travelled for motion with uniform speed or uniform acceleration

**Dynamics**

*Sub topics covered: Balanced and unbalanced forces, Free-body diagram, Friction*

- apply Newton’s Laws to:

(i) describe the effect of balanced and unbalanced forces on a body

(ii) describe the ways in which a force may change the motion of a body (stating of Newton’s laws is not required) - identify forces acting on an object and draw free-body diagram(s) representing the forces acting on the object (for cases involving forces acting in at most 2 dimensions)
- recall and apply the relationship resultant force = mass × acceleration to new situations or to solve related problems explain the effects of friction on the motion of a body

**Mass, Weight and Density**

*Sub topics covered: Mass and weight, Gravitational field and field strength, Density*

- state that mass is a measure of the amount of substance in a body
- state that mass of a body resists a change in the state of rest or motion of the body (inertia)
- state that a gravitational field is a region in which a mass experiences a force due to gravitational attraction
- define gravitational field strength, g, as gravitational force per unit mass
- recall and apply the relationship weight= mass × gravitational field strength to new situations or to solve related problems
- distinguish between mass and weight
- recall and apply the relationship density = mass / volume to new situations or to solve related problems

**Turning effect of forces**

*Sub topics covered: Moments, Centre of gravity, Stability*

- describe the moment of a force in terms of its turning effect and relate this to everyday examples
- recall and apply the relationship moment of a force (or torque) = force × perpendicular distance from the pivot to new - situations or to solve related problems
- state the principle of moments for a body in equilibrium
- apply the principle of moments to new situations or to solve related problems
- show understanding that the weight of a body may be taken as acting at a single point known as its centre of gravity
- describe qualitatively the effect of the position of the centre of gravity on the stability of objects

**Pressure**

- define the term pressure in terms of force and area
- recall and apply the relationship pressure = force / area to new situations or to solve related problems

**Energy, work and power**

*Sub topics covered: Energy conversion and conservation, Work, Power*

- show understanding that kinetic energy, potential energy (chemical, gravitational, elastic), light energy, thermal energy, electrical energy and nuclear energy are examples of different forms of energy
- state the principle of the conservation of energy and apply the principle to new situations or to solve related problems state that kinetic energy Ek=12mv2 and gravitational potential energy Ep=mgh (for potential energy changes near the Earth’s surface)
- apply the relationships for kinetic energy and potential energy to new situations or to solve related problems
- recall and apply the relationship work done = force × distance moved in the direction of the force to new situations or to solve related problems
- recall and apply the relationship power = work done / time taken to new situations or to solve related problems

**SECTION III: THERMAL PHYSICS**

In this section, students will start learning about thermal physics, and how heat or thermal energy transfer can be explained and predicted at the molecular level.

**Kinetic model of matter**

*Sub topics covered: States of matter, Kinetic model*

- compare the properties of solids, liquids and gases
- describe qualitatively the molecular structure of solids, liquids and gases, relating their properties to the forces and distances between molecules and to the motion of the molecules
- describe the relationship between the motion of molecules and temperature

**Transfer of thermal energy**

*Sub topics covered: States of matter | Kinetic model*

- show understanding that thermal energy is transferred from a region of higher temperature to a region of lower temperature
- describe, in molecular terms, how energy transfer occurs in solids
- describe, in terms of density changes, convection in fluids
- explain that energy transfer of a body by radiation does not require a material medium and the rate of energy transfer is affected by:

(i) colour and texture of the surface

(ii) surface temperature

(iii) surface area - apply the concept of thermal energy transfer to everyday applications

**Thermal properties of matter**

*Sub topics covered: Internal energy, Melting, boiling and evaporation*

- describe a rise in temperature of a body in terms of an increase in its internal energy (random thermal energy)
- describe melting / solidification and boiling / condensation as processes of energy transfer without a change in temperature
- explain the difference between boiling and evaporation

**SECTION IV: WAVES**

In this section, students will examine the nature of waves in terms of the coordinated movement of particles. The topic then moves on to wave propagation and its uses by studying the properties of light, electromagnetic waves and sound, as well as their applications in wireless communication, home appliances, medicine and industry.

**General wave properties**

*Sub topics covered: Describing wave motion, Wave terms, Longitudinal and transverse waves*

- describe what is meant by wave motion as illustrated by vibrations in ropes and springs and by waves in a ripple tank
- show understanding that waves transfer energy without transferring matter
- define speed, frequency, wavelength, period and amplitude
- state what is meant by the term wavefront
- recall and apply the relationship velocity = frequency × wavelength to new situations or to solve related problems
- compare transverse and longitudinal waves and give suitable examples of each

**Light**

*Sub topics covered: Reflection of light, Refraction of light, Thin converging lenses*

- recall and use the terms for reflection, including normal, angle of incidence and angle of reflection
- state that, for reflection, the angle of incidence is equal to the angle of reflection and use this principle in constructions, measurements and calculations
- recall and use the terms for refraction, including normal, angle of incidence and angle of refraction
- recall and apply the relationship sin i / sin r = constant to new situations or to solve related problems
- define refractive index of a medium in terms of the ratio of speed of light in vacuum and in the medium
- explain the terms critical angle and total internal reflection
- describe the action of a thin converging lens on a beam of light
- define the term focal length for a converging lens
- draw ray diagrams to illustrate the formation of real and virtual images of an object by a thin converging lens

**Electromagnetic Spectrum**

*Sub topics covered: Properties of electromagnetic waves, Applications of electromagnetic waves*

- state that all electromagnetic waves are transverse waves that travel with the same speed in vacuum and state the magnitude of this speed
- describe the main components of the electromagnetic spectrum
- state examples of the use of the following components:

(i) radiowaves (e.g. radio and television communication)

(ii) microwaves (e.g. microwave oven and satellite television)

(iii) infra-red (e.g. infra-red remote controllers and intruder alarms)

(iv) light (e.g. optical fibres for medical uses and telecommunications)

(v) ultra-violet (e.g. sunbeds and sterilisation)

(vi) X-rays (e.g. radiological and engineering applications)

(vii) gamma rays (e.g. medical treatment)

**Sound**

*Sub topics covered: Sound waves, Speed of sound, Echo*

- describe the production of sound by vibrating sources
- describe the longitudinal nature of sound waves in terms of the processes of compression and rarefaction
- explain that a medium is required in order to transmit sound waves and the speed of sound differs in air, liquids and solids
- relate loudness of a sound wave to its amplitude and pitch to its frequency
- describe how the reflection of sound may produce an echo, and how this may be used for measuring distances

**SECTION V: ELECTRICITY AND MAGNETISM**

In this section, students will study about moving charges and the concepts of current, voltage and resistance. They will also learn how these concepts are applied to simple circuits and household electricity.

**Static Electricity**

*Sub topics covered: Principles of electrostatics, Electric field*

- state that there are positive and negative charges and that charge is measured in coulombs
- state that unlike charges attract and like charges repel
- describe an electric field as a region in which an electric charge experiences a force
- draw the electric field of an isolated point charge and recall that the direction of the field lines gives the direction of the - - force acting on a positive test charge
- draw the electric field pattern between two isolated point charges

**Current of Electricity**

*Sub topics covered: Conventional current and electron flow, Electromotive force, Potential difference, Resistance*

- state that current is a rate of flow of charge and that it is measured in amperes
- distinguish between conventional current and electron flow
- recall and apply the relationship charge = current × time to new situations or to solve related problems
- define electromotive force (e.m.f.) as the work done by a source in driving a unit charge around a complete circuit
- state that the e.m.f. of a source and the potential difference (p.d.) across a circuit component is measured in volts
- define the p.d. across a component in a circuit as the work done to drive a unit charge through the component
- state the definition that resistance = p.d. / current
- apply the relationship R = V / I to new situations or to solve related problems
- describe an experiment to determine the resistance of a metallic conductor using a voltmeter and an ammeter, and make the necessary calculations
- recall and apply the formulae for the effective resistance of a number of resistors in series and in parallel to new situations or to solve related problems
- recall and apply the relationship of the proportionality between resistance and the length and cross-sectional area of a wire to new situations or to solve related problems

**D.C Circuits**

*Sub topics covered: Current and potential difference in circuits, Series and parallel circuits*

- draw circuit diagrams with power sources (cell or battery), switches, lamps, resistors (fixed and variable), fuses, ammeters and voltmeters
- state that the current at every point in a series circuit is the same and apply the principle to new situations or to solve related problems
- state that the sum of the potential differences in a series circuit is equal to the potential difference across the whole circuit and apply the principle to new situations or to solve related problems
- state that the current from the source is the sum of the currents in the separate branches of a parallel circuit and apply the principle to new situations or to solve related problems
- state that the potential difference across the separate branches of a parallel circuit is the same and apply the principle to new situations or to solve related problems
- recall and apply the relevant relationships, including R = V / I and those for current, potential differences and resistors in series and in parallel circuits, in calculations involving a whole circuit

**Practical Electricity**

*Sub topics covered: Electric power and energy, Dangers of electricity, Safe use of electricity in the home*

- describe the use of the heating effect of electricity in appliances such as electric kettles, ovens and heaters
- recall and apply the relationships P=VI and E=VIt to new situations or to solve related problems
- calculate the cost of using electrical appliances where the energy unit is the kWh
- state the hazards of using electricity in the following situations

(i) damaged insulation

(ii) overheating of cables

(iii) damp conditions - explain the use of fuses and circuit breakers in electrical circuits and of fuse ratings
- explain the need for earthing metal cases and for double insulation
- state the meaning of the terms live, neutral and earth
- describe the wiring in a mains plug

(i) explain why switches, fuses, and circuit breakers are wired into the live conductor

**Magnetism and Electromagnetism**

*Sub topics covered: Laws of magnetism, Magnetic properties of matter, Magnetic field, Magnetic effect of a current, Application of the magnetic effect of a current, Force on a current-carrying conductor*

- state the properties of magnets
- describe induced magnetism
- describe electrical methods of magnetisation and demagnetisation
- distinguish between the properties and uses of temporary magnets (e.g. iron) and permanent magnets (e.g. steel)
- draw the magnetic field pattern around a bar magnet and between the poles of two bar magnets
- describe the plotting of magnetic field lines with a compass
- draw the pattern of the magnetic field due to currents in straight wires and in solenoids and state the effect on the magnetic field of changing the magnitude and / or direction of the current
- describe the application of the magnetic effect of a current in a circuit breaker
- describe experiments to show the force on a current-carrying conductor in a magnetic field, including the effect of reversing (i) the current (ii) the direction of the field
- deduce the relative directions of force, field and current when any two of these quantities are at right angles to each other using Fleming’s left-hand rule
- explain how a current-carrying coil in a magnetic field experiences a turning effect (recall of structure of an electric motor is not required)

**Chemistry**

*Note: The O Level Chemistry syllabus will change from 2023 onwards. The information below is based on the examination syllabus offered to school candidates up until 2022. Information on the new syllabus will be updated after the 2022 O Level examination.*

**SECTION I: EXPERIMENTAL CHEMISTRY**

Chemistry is typically an experimental science and relies primarily on practical work. In this section, students will examine the appropriate use of simple apparatus and chemicals, and their experimental techniques.

**Experimental Design**

- name appropriate apparatus for the measurement of time, temperature, mass and volume, including burettes, pipettes, measuring cylinders and gas syringes
- suggest suitable apparatus, given relevant information, for a variety of simple experiments, including collection of gases and measurement of rates of reaction

**Methods of purification and analysis**

-describe methods of separation and purification for the components of mixtures, to include:

(i) use of a suitable solvent, filtration and crystallisation or evaporation

(ii) distillation and fractional distillation

(iii) paper chromatography

- suggest suitable separation and purification methods, given information about the substances involved in the following types of mixtures:

(i) solid-solid

(ii) solid-liquid

(iii) liquid-liquid (miscible) - interpret paper chromatograms
- deduce from the given melting point and boiling point the identities of substances and their purity

**Identification of ions and gases**

- describe the use of aqueous sodium hydroxide and aqueous ammonia to identify the following aqueous cations: ammonium, calcium, copper(II), iron(II), iron(III), lead (II) and zinc
- describe tests to identify the following anions:

(i) carbonate (by the addition of dilute acid and subsequent use of limewater)

(ii) chloride (by reaction of an aqueous solution with nitric acid and aqueous silver nitrate)

(iii) nitrate (by reduction with aluminium and aqueous sodium hydroxide to ammonia and subsequent use of litmus paper)

(iv) sulfate (by reaction of an aqueous solution with nitric acid and aqueous barium nitrate) - describe tests to identify the following gases:

(i) ammonia (using damp red litmus paper)

(ii) carbon dioxide (using limewater)

(iii) chlorine (using damp litmus paper)

(iv) hydrogen (using a burning splint)

(v) oxygen (using a glowing splint)

(vi) sulfur dioxide (using acidified potassium manganate(VII))

**SECTION II: ATOMIC STRUCTURE AND STOICHIOMETRY**

In this section, students are introduced to one of the most important fundamental concept in chemistry - the idea of atoms and chemical bonding. Students are also introduced to the use of models and theories in the study of the structures of atoms, molecules and ions, and the bonding in elements and compounds.

**Kinetic Particle Theory**

- describe the solid, liquid and gaseous states of matter and explain their interconversion in terms of the kinetic particle theory and of the energy changes involved

**Atomic Structure**

- state the relative charges and approximate relative masses of a proton, a neutron and an electron
- describe, with the aid of diagrams, the structure of an atom as containing protons and neutrons (nucleons) in the nucleus and electrons arranged in shells (energy levels)
- define proton number (atomic number) and nucleon number (mass number)
- interpret and use symbols such as 612C
- define the term isotopes
- deduce the numbers of protons, neutrons and electrons in atoms and ions given proton and nucleon numbers

**Structure and properties of materials**

- describe the differences between elements, compounds and mixtures

**Ionic Bonding**

- describe the formation of ions by electron loss / gain in order to obtain the electronic configuration of a noble gas
- describe the formation of ionic bonds between metals and non-metals, e.g. NaCl; MgCl2 relate the physical properties (including electrical property) of ionic compounds to their lattice structure

**Covalent Bonding**

- describe the formation of a covalent bond by the sharing of a pair of electrons in order to gain the electronic configuration of a noble gas
- describe, using ‘dot and cross’ diagrams, the formation of covalent bonds between non-metallic elements, e.g. H2, O2, H2O, CH4 and CO2
- deduce the arrangement of electrons in other covalent molecules
- relate the physical properties (including electrical property) of covalent substances to their structure and bonding

**Formulae, Stoichiometry and the Mole Concept**

- state the symbols of the elements and formulae of the compounds mentioned in the syllabus
- deduce the formulae of simple compounds from the relative numbers of atoms present and vice versa
- deduce the formulae of ionic compounds from the charges on the ions present and vice versa
- interpret chemical equations with state symbols
- construct chemical equations, with state symbols, including ionic equations
- define relative atomic mass, Ar
- define relative molecular mass, Mr , and calculate relative molecular mass (and relative formula mass) as the sum of relative atomic masses
- calculate stoichiometric reacting masses and volumes of gases (one mole of gas occupies 24 dm3 at room temperature and pressure); calculations involving the idea of limiting reactants may be set (knowledge of the gas laws and the calculations of gaseous volumes at different temperatures and pressures are not required)
- apply the concept of solution concentration (in mol/dm3 or g/dm3 )to process the results of volumetric experiments and to solve simple problems

**SECTION III: CHEMISTRY OF REACTIONS**

In this section, students examine the chemical decomposition of substance by electrolysis, characteris properties and reactions of acids, bases and salts, the factors affecting the rate of reaction and the energy changes during a reaction.

**Energy Changes**

- describe the term exothermic as a process or chemical reaction which transfers energy, often in the form of heat, to the surroundings and may be detected by an increase in temperature, e.g. the reaction between sodium hydroxide and hydrochloric acid
- describe the term endothermic as a process or chemical reaction which takes in energy, often in the form of heat, from the surroundings and may be detected by a decrease in temperature, e.g. the dissolving of ammonium nitrate in water

**Speed of reaction**

- describe the effect of concentration, pressure, particle size and temperature on the speeds of reactions and explain these effects in terms of collisions between reacting particles
- interpret data obtained from experiments concerned with speed of reaction

**Redox**

- define oxidation and reduction (redox) in terms of oxygen / hydrogen gain / loss
- define redox in terms of electron transfer and changes in oxidation state
- describe the use of aqueous potassium iodide and acidified potassium manganate(VII) in testing for oxidising and reducing agents from the resulting colour changes

**Acids and Bases**

describe the meanings of the terms acid and alkali in terms of the ions they produce in aqueous solution and their effects on Universal Indicator describe how to test hydrogen ion concentration and hence relative acidity using Universal Indicator and the pH scale describe the characteristic properties of acids as in reactions with metals, bases and carbonates describe the reaction between hydrogen ions and hydroxide ions to produce water, H+ + OH- → H2O as neutralisation describe the importance of controlling the pH in soils and how excess acidity can be treated using calcium hydroxide describe the characteristic properties of bases as in reactions with acids and with ammonium salts classify oxides as acidic, basic, amphoteric or neutral based on metallic / non-metallic character

**Salts**

describe the techniques used in the preparation, separation and purification of salts as examples of some of the techniques specified in chemistry suggest a method of preparing a given salt from suitable starting materials, given appropriate information

**SECTION IV: PERIODICITY**

In this section, students examine the periodic trends and group properties of elements, the occurrence of metals and their properties, reactivity and uses. Students should be able to appreciate the development of the Periodic Table and hence to envisage that scientific knowledge changes and accumulates over time, and also the need for conserving some of the finite resources.

**Periodic trends**

- describe the Periodic Table as an arrangement of the elements in the order of increasing proton (atomic) number
- describe how the position of an element in the Periodic Table is related to proton number and electronic structure
- explain the similarities between the elements in the same group of the Periodic Table in terms of their electronic structure
- describe the change from metallic to non-metallic character from left to right across a period of the Periodic Table
- describe the relationship between group number, number of valence electrons and metallic / non-metallic character
- predict the properties of elements in Group I and Group VII using the Periodic Table

**Group properties**

- describe lithium, sodium and potassium in Group I (the alkali metals) as a collection of relatively soft, low-density metals showing a trend in melting point and in their reaction with water
- describe chlorine, bromine and iodine in Group VII (the halogens) as a collection of diatomic non-metals showing a trend in colour, state and their displacement reactions with solutions of other halide ions
- describe the lack of reactivity of the elements in Group 0 (the noble gases) in terms of their electronic structures

**Properties of metals**

- describe the general physical properties of metals as solids having high melting and boiling points, being malleable and good conductors of heat and electricity
- describe alloys as a mixture of a metal with another element, e.g. brass; stainless steel identify representations of metals and alloys from diagrams of structures

**Reactivity series**

- place in order of reactivity calcium, copper, (hydrogen), iron, lead, magnesium, potassium, silver, sodium and zinc, by reference to the reactions, if any, of the metals with water, steam and dilute hydrochloric acid
- deduce the order of reactivity from a given set of experimental results

**Extraction of metals**

- describe the ease of obtaining metals from their ores by relating the elements to their positions in the reactivity series

**Recycling of metals**

- describe metal ores as a finite resource and hence the need to recycle metals, e.g. the recycling of iron
- discuss the social, economic and environmental issues of recycling metals

**Iron**

- describe and explain the essential reactions in the extraction of iron using haematite, limestone and coke in the blast furnace
- describe the essential conditions for the corrosion (rusting) of iron as the presence of oxygen and water; prevention of rusting can be achieved by placing a barrier around the metal, e.g. painting; greasing; plastic coating

**SECTION IV: ATMOSHPHERE**

In this section, the sources of air pollutants and their effects are examined. By the end of this section, students are expected to value the knowledge of the hazardous nature of pollutants and the environmental issues related to air pollution.

**Air**

- describe the volume composition of gases present in dry air as being approximately 78% nitrogen, 21% oxygen and the remainder being noble gases (with argon as the main constituent) and carbon dioxide name some common atmospheric pollutants, e.g. carbon monoxide; methane; nitrogen oxides (NO and NO2); ozone; sulfur dioxide; unburned hydrocarbons
- state the sources of these pollutants as:

(i) carbon monoxide from incomplete combustion of carbon-containing substances

(ii) nitrogen oxides from lightning activity and internal combustion engines

(iii) sulfur dioxide from volcanoes and combustion of fossil fuels - discuss some of the effects of these pollutants on health and on the environment:

(i) the poisonous nature of carbon monoxide

(ii) the role of nitrogen dioxide and sulfur dioxide in the formation of ‘acid rain’ and its effects on respiration and buildings

**SECTION VI: ORGANIC CHEMISTRY**

In this section, students examine the sources of fuels, some basic concepts of organic chemistry such as homologous series, functional group, general formula and structural formula, and polymers. Students should be able to identify and name unbranched alkanes, alkenes, alcohols and carboxylic acids.

**Fuels and crude oil**

- name natural gas, mainly methane, and petroleum as sources of energy
- describe petroleum as a mixture of hydrocarbons and its separation into useful fractions by fractional distillation
- name the following fractions and state their uses: (i) petrol (gasoline) as a fuel in cars

(ii) naphtha as the feedstock for the petrochemical industry

(iii) paraffin (kerosene) as a fuel for heating and cooking and for aircraft engines

(iv) diesel as a fuel for diesel engines

(v) lubricating oils as lubricants and as a source of polishes and waxes

(vi) bitumen for making road surfaces

**Alkanes**

- describe a homologous series as a group of compounds with a general formula, similar chemical properties and showing a gradation in physical properties as a result of increase in the size and mass of the molecules, e.g. melting and boiling points; viscosity; flammability
- describe the alkanes as a homologous series of saturated hydrocarbons with the general formula CnH2n+2
- draw the structures of unbranched alkanes, C1 to C3 and name the unbranched alkanes, methane to propane
- describe the properties of alkanes (exemplified by methane) as being generally unreactive except in terms of combustion and substitution by chlorine

**Alkenes**

- describe the alkenes as a homologous series of unsaturated hydrocarbons with the general formula CnH2n
- draw the structures of unbranched alkenes, C2 to C3 and name the unbranched alkenes, ethene to propene
- describe the manufacture of alkenes and hydrogen by cracking hydrocarbons and recognise that cracking is essential to match the demand for fractions containing smaller molecules from the refinery process
- describe the difference between saturated and unsaturated hydrocarbons from their molecular structures and by using aqueous bromine
- describe the properties of alkenes (exemplified by ethene) in terms of combustion and the addition reactions with bromine and hydrogen
- state the meaning of polyunsaturated when applied to food products
- describe the manufacture of margarine by the addition of hydrogen to unsaturated vegetable oils to form a solid product
- describe the formation of poly(ethene) as an example of addition polymerisation of ethene as the monomer
- state some uses of poly(ethene) as a typical plastic, e.g. plastic bags; clingfilm
- deduce the structure of the addition polymer product from a given monomer and vice versa
- describe the pollution problems caused by the disposal of non-biodegradable plastics

**Alcohols**

- describe the alcohols as a homologous series containing the –OH group
- draw the structures of unbranched alcohols, C1 to C3 and name the unbranched alcohols, methanol to propanol
- describe the properties of alcohols in terms of combustion and oxidation to carboxylic acids
- describe the formation of ethanol by fermentation of glucose

**Carboxylic acids**

- describe the carboxylic acids as organic acids containing the –COOH group
- describe the formation of ethanoic acid by the oxidation of ethanol by atmospheric oxygen or acidified potassium manganate(VII)

**Biology**

*Note: The O Level Biology syllabus will change from 2023 onwards. The information below is based on the examination syllabus offered to school candidates up until 2022. Information on the new syllabus will be updated after the 2022 O Level examination.*

**SECTION I: PRINCIPLES OF BIOLOGY**

In this section, students will study two key principles of Biology - correlation of structure to function and that specialisation results in the division of labour, which enables the cell to effectively carry out a number of vital life processes. A strong foundation in the principles of this subject will pave the way for students to master the content in subsequent topics.

**Cell structure and organisation**

*Sub topics covered: Plant and animal cells, Specialised cells, tissues and organs*

- identify cell structures (including organelles) of typical plant and animal cells from diagrams, photomicrographs and as seen under the light microscope using prepared slides and fresh material treated with an appropriate temporary staining technique:

(i) chloroplasts

(ii) cell membrane

(iii) cell wall

(iv) cytoplasm

(v) cell vacuoles (large, sap-filled in plant cells, small, temporary in animal cells)

(vi) nucleus - identify the following organelles from diagrams and electronmicrographs: (i) mitochondria

(ii) ribosomes - state the functions of the organelles identified above
- compare the structure of typical animal and plant cells
- state, in simple terms, the relationship between cell function and cell structure for the following:

(i) absorption – root hair cells

(ii) conduction and support – xylem vessels

(iii) transport of oxygen – red blood cells - differentiate cell, tissue, organ and organ system

**Movement of substances**

*Sub topics covered: Diffusion, Osmosis*

- define diffusion and describe its role in nutrient uptake and gaseous exchange in plants and humans
- define osmosis and describe the effects of osmosis on plant and animal tissues

**Biological Molecules**

*Sub topics covered: Water and living organisms, Carbohydrates, fats and proteins, Enzymes*

- state the roles of water in living organisms
- describe and carry out tests for

(i) starch (iodine in potassium iodide solution)

(ii) reducing sugars (Benedict’s solution)

(iii) protein (biuret test)

(iv) fats (ethanol emulsion) - state that large molecules are synthesised from smaller basic units (i) glycogen from glucose

(ii) polypeptides and proteins from amino acids

(iii) lipids such as fats from glycerol and fatty acids - explain enzyme action in terms of the ‘lock and key’ hypothesis (explain the mode of action of enzymes in terms of an active site, enzyme-substrate complex and enzyme specificity)
- investigate and explain the effects of temperature and pH on the rate of enzyme-catalysed reactions

**SECTION II: MAINTENANCE AND REGULATION OF LIFE PROCESSES**

When studying biology, it is inevitable for students to understand how life is sustained. In humans, the maintenance and regulation of life processes include factors such as nutrition, transport, respiration, excretion, homeostasis and co-ordination and response.

**Nutrition in humans**

*Sub topics covered: Human alimentary canal, Chemical digestion, Absorption and assimilation*

describe the functions of main regions of the alimentary canal and the associated organs: mouth, salivary glands, oesophagus, stomach, duodenum, pancreas, gall bladder, liver, ileum, colon, rectum, anus, in relation to ingestion, digestion, absorption, assimilation and egestion of food, as appropriate describe the functions of enzymes (e.g. amylase, maltase, protease, lipase) in digestion, listing the substrate and end-products state the function of the hepatic portal vein as the transport of blood rich in absorbed nutrients from the small intestine to the liver state the role of the liver in:

(i) the metabolism of glucose

(ii) the metabolism of amino acids and the formation of urea

(iii) the breakdown of alcohol

**Nutrition in plants**

*Sub topics covered: Leaf structure, Photosynthesis*

- identify the cellular and tissue structure of a dicotyledonous leaf, as seen in cross-section under the microscope and state their functions:

(i) distribution of chloroplasts – photosynthesis

(ii) stomata and mesophyll cells – gaseous exchange

(iii) vascular bundles – transport - state the equation, in words only, for photosynthesis
- describe the intake of carbon dioxide and water by plants
- state that chlorophyll traps light energy and converts it into chemical energy for the formation of carbohydrates and their subsequent storage
- investigate and state the effect of varying light intensity, carbon dioxide concentration and temperature on the rate of photosynthesis (e.g. in submerged aquatic plants)
- briefly explain why most forms of life are completely dependent on photosynthesis

**Transport in flowering plants**

Sub topics covered: Water and ion uptake, Transpiration and translocation

- identify the positions of xylem vessels and phloem in sections of a typical dicotyledonous stem and leaf, under the light microscope, and state their functions
- relate the structure and functions of root hairs to their surface area, and to water and ion uptake
- state that transpiration is the loss of water vapour from the stomata
- briefly explain the movement of water through the stem in terms of transpiration pull describe

(i) the effects of variation of air movement, temperature, humidity and light intensity on transpiration rate

(ii) how wilting occurs - define the term translocation as the transport of food in the phloem tissue

**Transport in humans**

*Sub topics covered: Circulatory system*

- name the main blood vessels to and from the heart, lungs, liver and kidney
- state the functions of blood

(i) red blood cells – haemoglobin and oxygen transport

(ii) plasma – transport of blood cells, ions, soluble food substances, hormones, carbon dioxide, urea, vitamins, plasma proteins

(iii) white blood cells – phagocytosis, antibody formation and tissue rejection

(iv) platelets – fibrinogen to fibrin, causing clotting - relate the structure of arteries, veins and capillaries to their functions
- describe the structure and function of the heart in terms of muscular contraction and the working of valves (histology of the heart muscle, names of nerves and transmitter substances are not required)
- describe coronary heart disease in terms of the occlusion of coronary arteries and list the possible causes, such as diet, stress, smoking, and the possible preventative measures

**Respiration in humans**

*Sub topics covered: Human gas exchange, Aerobic respiration, Anaerobic respiration*

- identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries and state their functions in human gas exchange
- state the characteristics of, and describe the role of, the exchange surface of the alveoli in gas exchange
- describe the effect of tobacco smoke and its major toxic components – nicotine, tar and carbon monoxide, on health
- define and state the equation, in words only, for aerobic respiration in humans
- define and state the equation, in words only, for anaerobic respiration in humans
- describe the effect of lactic acid in muscles during exercise

**Co-ordination and response in humans**

*Sub topics covered: Receptors (Eye), Nervous system (Neurones), Nervous System (Neurons)*

- state the relationship between receptors, the central nervous system and the effectors
- state the principal functions of component parts of the eye in producing a focused image of near and distant objects on the retina
- describe the pupil reflex in response to bright and dim light
- outline the functions of sensory neurones, relay neurones and motor neurones
- define a hormone as a chemical substance, produced by a gland, carried by the blood, which alters the activity of one or more specific target organs and is then destroyed by the liver
- state what is meant by an endocrine gland, with reference to the islets of Langerhans in the pancreas
- outline how the blood glucose concentration is regulated by insulin and glucagon

**SECTION III: CONTINUITY OF LIFE**

In this section, students will focus on understanding the processes involved in the continuity of life and how genetic information is passed from one generation to the next.

**Reproduction**

*Sub topics covered: Asexual reproduction, Sexual reproduction in plants, Sexual reproduction in humans, Sexually transmitted diseases*

- define asexual reproduction as the process resulting in the production of genetically identical offspring from one parent
- define sexual reproduction as the process involving the fusion of nuclei to form a zygote and the production of genetically dissimilar offspring
- state the functions of the sepals, petals, anthers and carpels
- outline the process of pollination
- describe the growth of the pollen tube and its entry into the ovule followed by fertilisation (production of endosperm and details of development are not required)
- identify on diagrams of the male reproductive system and give the functions of: testes, scrotum, sperm ducts, prostate gland, urethra and penis
- identify on diagrams of the female reproductive system and give the functions of: ovaries, oviducts, uterus, cervix and vagina
- briefly describe the menstrual cycle with reference to the alternation of menstruation and ovulation, the natural variation in its length, and the fertile and infertile phases of the cycle, with reference to the roles of oestrogen and progesterone only
- briefly describe fertilisation and early development of the zygote simply in terms of the formation of a ball of cells which becomes implanted in the wall of the uterus
- discuss the spread of human immunodeficiency virus (HIV) and methods by which it may be controlled

**Molecular Genetics**

*Sub topics covered: The structure of DNA, The role of DNA in protein synthesis*

- outline the relationship between genes, chromosomes, and DNA
- state the structure of DNA in terms of the bases, sugar and phosphate groups found in each of the nucleotides
- state the rule of complementary base pairing
- state that DNA is used to carry the genetic code (details of translation and transcription are not required)
- state that each gene

(i) is a sequence of nucleotides, as part of a DNA molecule

(ii) controls the production of one polypeptide

**Inheritance**

*Sub topics covered: The passage of information from parent to offspring, The nature of genes and alleles, and their role in determining the phenotype, Monohybrid crosses, Variation*

- define a gene as a unit of inheritance and distinguish clearly between the terms gene and allele
- describe the difference between continuous and discontinuous variation and give examples of each
- explain the terms dominant, recessive, homozygous, heterozygous, phenotype and genotype
- predict the results of simple crosses with expected ratios of 3:1 and 1:1, using the terms homozygous, heterozygous, F1 generation and F2 generation
- state why observed ratios often differ from expected ratios, especially when there are small numbers of progeny
- describe the determination of sex in humans – XX and XY chromosomes
- describe mutation as a change in the structure of a gene such as in sickle cell anaemia, or in the chromosome number such as the 47 chromosomes in a condition known as Down’s Syndrome
- name radiation and chemicals as factors which may increase the rate of mutation

**SECTION IV: MAN AND HIS ENVIRONMENT**

The web of life, a complex network of interactions amongs all living organisms. In this section, students will focus on the interrelationships between livings things and the environment. Students will learn about two major processes, which is firstly the cycling of nutrients and the flow of energy from sunlight to organisms further down the food chain.

As part of this environment, it is vital for humans to show a sense of responsbility for its maintenance.

**Organisms and their environment**

*Sub topics covered: Energy flow, Food chains and food webs, Carbon cycle, Effects of man on the ecosystem, Environmental biotechnology, Conservation*

- briefly describe the non-cyclical nature of energy flow
- establish the relationship of the following in food webs: producer, consumer, herbivore, carnivore, decomposer, food chain, trophic level
- describe energy losses between trophic levels and infer the advantages of short food chains
- interpret pyramids of numbers and biomass
- explain the importance of the carbon cycle and outline the role of forests and oceans as carbon sinks
- evaluate the effects of

(i) water pollution by sewage

(ii) pollution due to insecticides including bioaccumulation up food chains and impact on top carnivores - outline the roles of microorganisms in sewage treatment as an example of environmental biotechnology
- discuss reasons for conservation of species with reference to the maintenance of biodiversity and how this is done, e.g. management of fisheries and management of timber production