Companion PDF worksheet for Edexcel IGCSE Biology Lecture 41 - DNA, Genes and Chromosomes. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 3.14 - Understand that the genome is the entire DNA of an organism and that a gene is a section of a molecule of DNA that codes for a specific protein. Specification Point 3.15 - Understand that the nucleus of a cell contains chromosomes on which genes are located. Complete set of Chapter 5 Worksheets are available.

Companion PDF worksheet for Edexcel IGCSE Chemistry Lecture 13 - Covalent Bonding. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 1.44 - Know that a covalent bond is formed between atoms by the sharing of a pair of electrons. Specification Point 1.45 - Understand covalent bonds in terms of electrostatic attractions. Specification Point 1.46 - Understand how to use dot-and-cross diagrams to represent covalent bonds in a variety of molecules. Specification Point 1.47 - Explain why substances with a simple molecular structures are gases or liquids, or solids with low melting and boiling points. Specification Point 1.48 - Explain why the melting and boiling points of substances with simple molecular structures increase, in general, with increasing relative molecular mass. Specification Point 1.49 - Explain why substances with giant covalent structures are solids with high melting and boiling points. Specification Point 1.50 - Explain how the structures of diamond, graphite and fullerene influence their physical properties, including electrical conductivity and hardness. Specification Point 1.51 - Know that covalent compounds do not usually conduct electricity. Complete set of Chapter 3 Worksheets are available.

Companion PDF worksheet for Edexcel IGCSE Chemistry Lecture 31 - Organic Compounds. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 4.1 - Know that a hydrocarbon is a compound of hydrogen and carbon only. Specification Point 4.2 - Understand how to represent organic molecules using empirical formulae, molecular formulae, general formulae, structural formulae and displayed formulae. Specification Point 4.3 - Know what is meant by the terms homologous series, functional group and isomerism. Specification Point 4.4 - Understand how to name compounds relevant to this specification using the rules of IUPAC nomenclature. Specification Point 4.5 - Understand how to write the possible structural and displayed formulae of an organic molecule given its molecular formula. Specification Point 4.6 - Understand how to classify reactions of organic compounds as substitution, addition and combustion. Complete set of Chapter 7 Worksheets are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.8.2.2 - Regulation of transcription and translation. Complete set of Chapter 8 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.7.1 - Inheritance. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.7.4 - Populations in ecosystems. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 1.1 - Understand the three states of matter in terms of the arrangement, movement & energy of the particles. Specification Point 1.2 - Understand the interconversions between the three states of matter in terms of: The names of the interconversions. How they are achieved. The changes in arrangement, movement & energy of the particles. Complete set of Chapter 1 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.34 - Understand how the process of respiration produces ATP in living organisms. Specification Point 2.35 - Know that ATP provides energy for cells. Specification Point 2.36 - Describe the differences between aerobic and anaerobic respiration. Specification Point 2.37 - 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 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.1 - Understand the terms population, community, habitat and ecosystem. Specification Point 4.2 - Practical: investigate the population size of an organism in two different areas using quadrats. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.9 - Practical: Investigate food samples for the presence of glucose, starch, protein and fat. Complete set of Chapter 1 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.5.2.2 - The brain. Complete set of Chapter 5 Lectures are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 1 - Characteristics of Living Organisms.. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Covers the following in a modern, concise format: Specification Point 1.1 - Understand how living organisms share certain characteristics. Complete set of Chapter 1 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 4.2.1 - Principles of organisation. Complete set of Chapter 2 Lectures are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 61 - Genetic Modification. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 5.12 - Understand how restriction enzymes are used to cut DNA at specific sites and ligase enzymes are used to join pieces of DNA together. Specification Point 5.13 - Understand how plasmids and viruses can act as vectors, which take up pieces of DNA, and then insert this recombinant DNA into other cells. Specification Point 5.14 - Understand how large amounts of human insulin can be manufactured from genetically modified bacteria that are grown in a fermenter. Specification Point 5.15 - Understand how genetically modified plants can be used to improve food production. Specification Point 5.16 - Understand that the term transgenic means the transfer of genetic material from one species to a different species. Complete set of Chapter 7 Worksheets are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 59 - Fish Farming. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 5.9B - Understand the methods used to farm large numbers of fish to provide a source of protein, including maintaining water quality, controlling intraspecific and interspecific predation, controlling disease, removing waste products, controlling the quality and frequency of feeding, and selective breeding. Complete set of Chapter 7 Worksheets are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1.2 - Memory. Factors affecting the accuracy of eyewitness testimony: misleading information, including leading questions and post-event discussion; anxiety. Improving the accuracy of eyewitness testimony, including the use of the cognitive interview. Complete set of Chapter 2 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.55B -Understand how water is absorbed by root hair cells. Specification Point 2.56B -Understand that transpiration is the evaporation of water from the surface of a plant. Specification Point 2.57B -Understand how the rate of transpiration is affected by changes in humidity, wind speed, temperature and light intensity. Specification Point 2.58B - Practical: investigate the role of environmental factors in determining the rate of transpiration from a leafy shoot. Complete set of Chapter 3 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 2.7 - Explain why a series or parallel circuit is more appropriate for particular applications, including domestic lighting. Specification Point 2.8 - Understand how the current in a series circuit depends on the applied voltage and the number and nature of other components. Specification Point 2.9 - Describe how current varies with voltage in wires, resistors, metal filament lamps and diodes, and how to investigate this experimentally. Specification Point 2.10 - Describe the qualitative effect of changing resistance on the current in a circuit. Specification Point 2.11 - Describe the qualitative variation of resistance of light-dependent resistors (LDRs) with illumination and thermistors with temperature. Specification Point 2.12 - Know that lamps and LEDs can be used to indicate the presence of a current in a circuit. Specification Point 2.13 - Know and use the relationship between voltage, current and resistance. Complete set of Chapter 2 Lectures are available.