Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.22 - Understand that most phenotypic features are the result of polygenic inheritance rather than single genes. Specification Point 3.23 - Describe patterns of monohybrid inheritance using a genetic diagram. Specification Point 3.24 - Understand how to interpret family pedigrees. Specification Point 3.25 - Predict probabilities of outcomes from monohybrid crosses. Specification Point 3.26 - Understand how the sex of a person is controlled by one pair of chromosomes, XX in a female and XY in a male. Specification Point 3.27 - Describe the determination of the sex of offspring at fertilisation, using a genetic diagram. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1 - Know that chemical reactions in which heat energy is given out are described as exothermic, and those in which heat energy is taken in are described as endothermic. Specification Point 3.2 - Describe simple calorimetry experiments for reactions such as combustion, displacement, dissolving and neutralisation. Specification Point 3.3 - Calculate the heat energy change from a measured temperature change using the expression Q = mcΔT. Specification Point 3.4 - Calculate the molar enthalpy change (ΔH) from the heat energy change, Q. Specification Point 3.8 - Practical: investigate temperature changes accompanying some of the following types of change: salts dissolving in water, neutralisation reactions, displacement reactions and combustion reactions. Complete set of Chapter 6 Lectures are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 17 - Respiration. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Points 2.34 and 2.35 - Understand how the process of respiration produces ATP in living organisms. Know that ATP provides energy for cells. Specification Points 2.36 and 2.37 - Describe the differences between aerobic and anaerobic respiration. Know the word equation and the balanced chemical symbol equation for aerobic respiration in living organisms. Specification Point 2.38 - Know the word equation for anaerobic respiration in plants and in animals. Specification Point 2.39 - Practical: investigate the evolution of carbon dioxide and heat from respiring seeds or other suitable living organisms. Complete set of Chapter 2 Worksheets are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 6 - Food Tests. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 2.9 - Practical: Investigate food samples for the presence of glucose, starch, protein and fat. Complete set of Chapter 1 Worksheets are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 1.5C - Know what is meant by the term solubility in the units grams per 100 grams of solvent. Specification Point 1.6C - Understand how to plot and interpret solubility curves. Specification Point 1.7C - Practical: investigate the solubility of a solid in water at a specific temperature. Complete set of Chapter 1 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1.3 - Attachment. Romanian orphan studies and the effects of institutionalisation. Complete set of Chapter 3 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.31 - Understand how random fertilization produces genetic variation of offspring. Specification Point 3.32 - Know that in human cells the diploid number of chromosomes is 46 and the haploid number is 23. Specification Point 3.33 - Understand that variation within a species can be genetic, environmental, or a combination of both. Specification Point 3.34 - Understand that mutation is a rare, random change in genetic material that can be inherited. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.48C - Know that condensation polymerisation, in which a dicarboxylic acid reacts with a diol, produces a polyester and water. Specification Point 4.49C - Understand how to write the structural and displayed formula of a polyester, showing the repeat unit, given the formulae of the monomers from which it is formed including the reaction of ethanedioic acid and ethanediol. Specification Point 4.50C - Know that some polyesters, known as biopolyesters, are biodegradable. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.4.1.1 - The photosynthetic reaction. Specification Point 4.4.1.3 - Uses of glucose from photosynthesis. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.6.1.5 - DNA structure. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.1 - Understand the classification of employment by economic sector (primary, secondary, tertiary and quaternary) and the reasons for the differences in the employment structures in countries at different levels of development. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.2.1 - Approaches in psychology. Humanistic psychology: free will, self-actualisation and Maslow’s hierarchy of needs, focus on the self, congruence, the role of conditions of worth. The influence on counselling psychology. Complete set of Chapter 5 Lectures are available.

Companion PDF worksheet for Edexcel IGCSE Chemistry Lecture 17 - Group 7 Elements. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 2.5 - Know the colours, physical states (at room temperature) and trends in physical properties of chlorine, bromine and iodine. Specification Point 2.6 - Use knowledge of trends in group 7 to predict the properties of other halogens. Specification Point 2.7 - Understand how displacement reactions involving halogens and halides provide evidence for the trend in reactivity in group 7. Specification Point 2.8C - Explain the trend in reactivity in group 7 in terms of electronic configurations. Complete set of Chapter 4 Worksheets are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.2.3.1 - Scientific Processes. Aims: stating aims, the difference between aims and hypotheses. Hypotheses: directional and non-directional. Sampling: the difference between population and sample; sampling techniques including: random, systematic, stratified, opportunity and volunteer; implications of sampling techniques, including bias and generalisation. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1 - Use the following units: degree (°), hertz (Hz), metre (m), metre/second (m/s) and second (s). Specification Point 3.2 - Explain the difference between longitudinal and transverse waves. Specification Point 3.3 - Know the definitions of amplitude, wavefront, frequency, wavelength and period of a waves. Specification Point 3.4 - Know that waves transfer energy and information without transferring matter. Specification Point 3.5 - Know and use the relationship between the speed, frequency and wavelength of a wave. Specification Point 3.6 - Use the relationship between frequency and time period. Complete set of Chapter 3 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.1 - Use a variety of energy units. Specification Point 4.2 - Describe energy transfers involving energy stores. Specification Point 4.3 - Use the principle of conservation of energy. Specification Point 4.4 - Know and use the relationship between efficiency, useful energy output and total energy output. Specification Point 4.5 - Describe a variety of everyday and scientific devices and situations, explaining the transfer of the input energy in terms of the above relationship, including their representation by Sankey diagrams. Complete set of Chapter 4 Lectures are available.

Companion PDF worksheet for Edexcel IGCSE Physics Lecture 30 - Fission and Fusion. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 7.17 - Know that nuclear reactions, including fission, fusion and radioactive decay, can be a source of energy. Specification Point 7.18 - Understand how a nucleus of U-235 can be split by collision with a neutron, and that this process releases energy as kinetic energy of the fission products. Specification Point 7.19 -Know that the fission of U-235 produces two radioactive daughter nuclei and a small number of neutrons. Specification Point 7.20 - Describe how a chain reaction can be set up if the neutrons produced by one fission strike other U-235 nuclei. Specification Point 7.21 - Describe the role played by the control rods and moderator in the fission process. Specification Point 7.22 - Understand the role of shielding around a nuclear reactor. Specification Point 7.23 - Explain the difference between nuclear fusion and nuclear fission. Specification Point 7.24 - Describe nuclear fusion as the creation of larger nuclei resulting in a loss of mass from smaller nuclei, accompanied by a release of energy. Specification Point 7.25 - Know that fusion is the energy source for stars. Specification Point 7.26 - Explain why nuclear fusion does not happen at low temperatures and pressures, due to electrostatic repulsion of protons. Complete set of Chapter 7 Worksheets are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.3.9 - Forensic psychology. Offender profiling: the top-down approach, including organised and disorganised types of offender; the bottom-up approach, including investigative psychology; geographical profiling. Complete set of Chapter 16 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.2.3.3 - Inferential Testing. Introduction to statistical testing; the sign test. When to use the sign test; calculation of the sign test. Probability and significance: use of statistical tables and critical values in interpretation of significance; Type I and Type II errors. Factors affecting the choice of statistical test, including level of measurement and experimental design. When to use the following tests: Spearman’s rho, Pearson’s r, Wilcoxon, Mann-Whitney, related t-test, unrelated t-test and Chi-Squared test. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1.1.3 - Electron configuration. Complete set of Chapter 1 Lectures are available.