Companion PDF worksheet for Edexcel IGCSE Biology Lecture 57 - Crop Production. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 5.1 - Describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops. Specification Point 5.2 - Understand the effects on crop yield of increased carbon dioxide and increased temperature in glasshouses. Specification Point 5.3 - Understand how the use of fertiliser can increase crop yield. Specification Point 5.4 - Understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants. Complete set of Chapter 7 Worksheets are available.

Powerpoint lecture and associated PDF worksheet covering the following in a modern, concise format: Specification Point 5.5 - Understand the role of yeast in the production of food including bread. Specification Point 5.6 - Practical: investigate the role of anaerobic respiration by yeast in different conditions. Specification Point 5.7 - Understand the role of bacteria (Lactobacillus) in the production of yoghurt. Specification Point 5.8 - Understand the use of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including aseptic precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of microorganisms. Complete set of Chapter 7 Lessons are available.

Powerpoint lecture and associated PDF worksheet covering the following in a modern, concise format: Specification Point 5.17B - Describe the process of micropropagation (tissue culture) in which explants are grown in vitro. Specification Point 5.18B - Understand how micropropagation can be used to produce commercial quantities of genetically identical plants with desirable characteristics. Specification Point 5.19B - Describe the stages in the production of cloned mammals involving the introduction of a diploid nucleus from a mature cell into an enucleated egg cell, illustrated by Dolly the sheep. Complete set of Chapter 7 Lessons are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 53 - The Carbon Cycle. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 4.10 - Describe the stages in the carbon cycle, including respiration, photosynthesis, decomposition and combustion. Complete set of Chapter 6 Worksheets are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.2.3.1 - Plant tissues. Specification Point 4.2.3.2 - Plant organ systems. Complete set of Chapter 2 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1.2 - Memory. Explanations for forgetting: proactive and retroactive interference and retrieval failure due to absence of cues. Complete set of Chapter 2 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.38C - Know that esters contain the functional group -COO-. Specification Point 4.39C - Know that ethyl ethanoate is the ester produced when ethanol and ethanoic acid react in the presence of an acid catalyst. Specification Point 4.40C - Understand how to write the structural and displayed formulae of ethyl ethanoate. Specification Point 4.41C - Understand how to write the structural and displayed formulae of an ester, given the name or formula of the alcohol and carboxylic acid from which it is formed and vice versa. Specification Point 4.42C - Know that esters are volatile compounds with distinctive smells and are used as food flavourings and in perfumes. Specification Point 4.43C - Practical: prepare a sample of an ester such as ethyl ethanoate. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.19 - Know the general formula for alkanes. Specification Point 4.20 - Explain why alkanes are classified as saturated hydrocarbons. Specification Point 4.21 - Understand how to draw the structural and displayed formulae for alkanes with up to five carbon atoms in the molecule, and to name the unbranched-chain isomers. Specification Point 4.22 - Describe the reactions of alkanes with halogens in the presence of ultraviolet radiation, limited to mono-substitution. Specification Point 4.23 - Know that alkenes contain a particular functional group (C=C). Specification Point 4.24 - Know the general formula for alkenes. Specification Point 4.25 - Explain why alkenes are classified as unsaturated hydrocarbons. Specification Point 4.26 - Understand how to draw the structural and displayed formulae for alkenes with up to four carbon atoms in the molecule, and name the unbranched-chain isomers. Specification Point 4.27 -Describe the reactions of alkenes with bromine to produce dibromoalkanes. Specification Point 4.28 - Describe how bromine water can be used to distinguish between an alkane and an alkene. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.6.1.1 - Sexual and asexual reproduction. Specification Point 4.6.1.2 - Meiosis. Specification Point 4.6.1.3 - Advantages and disadvantages of sexual and asexual reproduction. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.6.1.6 - Genetic inheritance. Specification Point 4.6.1.7 - Inherited disorders. Specification Point 4.6.1.8 - Sex determination. Specification Point 4.6.3.3 - The understanding of genetics. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.6.3.2 - Speciation. Specification Point 4.6.3.4 - Evidence for evolution. Specification Point 4.6.3.7 - Resistant bacteria. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.6.1.4 - DNA and the genome. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.3 - Understand ways to prepare for earthquakes (warning and evacuation, building design, remote sensing and GIS). Specification Point 3.3 - Understand short-term responses and relief (emergency aid, shelter and supplies). Specification Point 3.3 - Understand longer-term planning (risk assessment, hazard mapping and rebuilding programmes). Complete set of Chapter 3 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1 - Understand the characteristics, distribution and measurement of different types of natural hazards including tropical cyclones, earthquakes and volcanoes. Complete set of Chapter 3 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 1.4 - Assessment of hazardous fieldwork skills. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.2 - Understand informal employment: causes (economic development, rural-urban migration) and characteristics (advantages and disadvantages) in a named megacity. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.1 - Understand the reasons for the changes in the numbers of people employed in each economic sector, including the availability of raw materials, globalisation, mechanisation, demographic changes and government policies. Specification Point 4.2 - Understand the positive and negative impacts of economic sector shifts in a named developed and a named developing or emerging country. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 1.4 - Assessment of river fieldwork skills. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 6.1 - Understand the contrasting trends in urbanisation over the last 50 years in different parts of the world, including the processes of suburbanisation and counter-urbanisation. Complete set of Chapter 7 Lectures are available.