Designed for the new specification IGCSE Edexcel course but can be used for other examination boards. Covers: © Cycles within ecosystems 4.10 describe the stages in the carbon cycle, including respiration, photosynthesis, decomposition and combustion 4.11B describe the stages in the nitrogen cycle, including the roles of nitrogen fixing bacteria, decomposers, nitrifying bacteria and denitrifying bacteria (specific names of bacteria are not required)

Designed for the new specification AQA GCSE course but can be modified for other exam boards. 17 slides covering Cell division (chromosomes, mitosis and the cell cycle) By the end of the powerpoint students would have covered: 4.1.2.1 Chromosomes The nucleus of a cell contains chromosomes made of DNA molecules. Each chromosome carries a large number of genes. In body cells the chromosomes are normally found in pairs. **4.1.2.2 Mitosis and the cell cycle ** Cells divide in a series of stages called the cell cycle. Students should be able to describe the stages of the cell cycle, including mitosis. During the cell cycle the genetic material is doubled and then divided into two identical cells. Before a cell can divide it needs to grow and increase the number of sub-cellular structures such as ribosomes and mitochondria. The DNA replicates to form two copies of each chromosome. In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides. Finally the cytoplasm and cell membranes divide to form two identical cells. Students need to understand the three overall stages of the cell cycle but do not need to know the different phases of the mitosis stage. Cell division by mitosis is important in the growth and development of multicellular organisms. Students should be able to recognise and describe situations in given contexts where mitosis is occurring.

Designed for the new specification AQA GCSE course but can be modified for other exam boards. 32 slides covering Cell structure (cell specialisation and cell differentiation). By the end of the powerpoint students would have covered: **4.1.1.3 Cell specialisation ** Students should be able to, when provided with appropriate information, explain how the structure of different types of cell relate to their function in a tissue, an organ or organ system, or the whole organism. Cells may be specialised to carry out a particular function: sperm cells, nerve cells and muscle cells in animals root hair cells, xylem and phloem cells in plants. **4.1.1.4 Cell differentiation ** Students should be able to explain the importance of cell differentiation. As an organism develops, cells differentiate to form different types of cells. Most types of animal cell differentiate at an early stage. Many types of plant cells retain the ability to differentiate throughout life. In mature animals, cell division is mainly restricted to repair and replacement. As a cell differentiates it acquires different sub-cellular structures to enable it to carry out a certain function. It has become a specialised cell.

Designed for the new specification AQA GCSE course but can be modified for other exam boards. 12 slides covering Active transport . By the end of the powerpoint students would have covered: Active transport moves substances from a more dilute solution to a more concentrated solution (against a concentration gradient). This requires energy from respiration. Active transport allows mineral ions to be absorbed into plant root hairs from very dilute solutions in the soil. Plants require ions for healthy growth. It also allows sugar molecules to be absorbed from lower concentrations in the gut into the blood which has a higher sugar concentration. Sugar molecules are used for cell respiration. Students should be able to: describe how substances are transported into and out of cells by diffusion, osmosis and active transport explain the differences between the three processes.

Designed for the new specification AQA GCSE course but can be modified for other exam boards. 32 slides covering Diffusion. (contains a optional practical) By the end of the powerpoint students would have covered: Substances may move into and out of cells across the cell membranes via diffusion. Diffusion is the spreading out of the particles of any substance in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration. Some of the substances transported in and out of cells by diffusion are oxygen and carbon dioxide in gas exchange, and of the waste product urea from cells into the blood plasma for excretion in the kidney. Students should be able to explain how different factors affect the rate of diffusion. Factors which affect the rate of diffusion are: the difference in concentrations (concentration gradient) the temperature the surface area of the membrane. A single-celled organism has a relatively large surface area to volume ratio. This allows sufficient transport of molecules into and out of the cell to meet the needs of the organism. Students should be able to calculate and compare surface area to volume ratios. Students should be able to explain the need for exchange surfaces and a transport system in multicellular organisms in terms of surface area to volume ratio. Students should be able to explain how the small intestine and lungs in mammals, gills in fish, and the roots and leaves in plants, are adapted for exchanging materials. In multicellular organisms, surfaces and organ systems are specialised for exchanging materials. This is to allow sufficient molecules tobe transported into and out of cells for the organism’s needs. The effectiveness of an exchange surface is increased by: having a large surface area a membrane that is thin, to provide a short diffusion path (in animals) having an efficient blood supply (in animals, for gaseous exchange) being ventilated.

Designed for the new specification AQA GCSE course but can be modified for other exam boards. 15 slides covering animal and plant cells. By the end of the powerpoint students would have covered: **4.1.1.2 Animal and plant cells ** Students should be able to explain how the main sub-cellular structures, including the nucleus, cell membranes, mitochondria, chloroplasts in plant cells and plasmids in bacterial cells are related to their functions. Most animal cells have the following parts: -a nucleus -cytoplasm -a cell membrane -mitochondria -ribosomes. In addition to the parts found in animal cells, plant cells often have: -chloroplasts -a permanent vacuole filled with cell sap. Plant and algal cells also have a cell wall made of cellulose, which strengthens the cell. Students should be able to use estimations and explain when they should be used to judge the relative size or area of sub-cellular structures.

Designed for the new specification AQA GCSE course but can be modified for other exam boards. 15 slides covering Eukaryotic and prokaryotic cells . By the end of the powerpoint students would have covered: **4.1.1.1 Eukaryotes and prokaryotes ** Plant and animal cells (eukaryotic cells) have a cell membrane, cytoplasm and genetic material enclosed in a nucleus. Bacterial cells (prokaryotic cells) are much smaller in comparison. They have cytoplasm and a cell membrane surrounded by a cell wall. The genetic material is not enclosed in a nucleus. It is a single DNA loop and there may be one or more small rings of DNA called plasmids. Students should be able to demonstrate an understanding of the scale and size of cells and be able to make order of magnitude calculations, including the use of standard form.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 35 slides coveringThe Structure of Neurones By the end of the powerpoint students would have covered: 8.1 know the structure and function of sensory, relay and motor neurones, including Schwann cells and myelination Powerpoint contains exam questions.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 17 slides coveringThe Structure of Neurones By the end of the powerpoint students would have covered: 8.5 understand the role of myelination in saltatory conduction. Powerpoint contains exam questions.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 24 slides coveringThe Structure of Neurones By the end of the powerpoint students would have covered: 8.7 understand how the effects of drugs can be caused by their influence on nerve impulse transmission, illustrated by nicotine, lidocaine and cobra venom alpha toxin, the use of L-DOPA in the treatment of Parkinson’s disease and the action of MDMA (ecstasy) Powerpoint contains exam questions.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 26 slides coveringThe Structure of Neurones By the end of the powerpoint students would have covered: 8.6 (i) know the structure and function of synapses in nerve impulse transmission, including the role of neurotransmitters and acetylcholine. Powerpoint contains exam questions.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 22 slides covering Lipids By the end of the powerpoint students would have covered: State the importance of lipids. Describe the structure of Triglycerides. Describe the differences between saturated and unsaturated fatty acids. Includes two practical/demo activities

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 41 slides covering Carbohydrates By the end of the powerpoint students would have covered: -What is the difference between monosaccharides, disaccharides and polysaccharides. -Explain how disaccharides are formed. -Be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles. -Use a semi-quantitative method with Benedict’s reagent to estimate the concentrations of reducing sugars and with iodine solution to estimate the concentrations of starch.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 37 slides covering Proteins By the end of the powerpoint students would have covered: Know the structure of protein. Describe how polypeptides are made. Describe the primary, secondary, tertiary and quaternary structure and function of proteins. Know the structure of a globular protein and a fibrous protein and understand how their structures relate to their functions. Use a semi-quantitative method to estimate protein concentration using biuret reagent and colour standards. Includes practical details and a task using molecular models.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 29 slides covering Fertilisation in animals By the end of the powerpoint students would have covered: 3.11 understand how mammalian gametes are specialised for their functions (including the acrosome in sperm and the zona pellucida in the egg cell). 3.12 know the process of fertilisation in mammals, including the acrosome reaction, the cortical reaction and the fusion of nuclei. Powerpoint contains exam questions.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 37 slides covering The chemistry of life (water) By the end of the powerpoint students would have covered: Understand the importance of water as a solvent in transport, including its dipole nature.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 21 slides covering Fertilisation in plants By the end of the powerpoint students would have covered: 3.13 know the process of fertilisation in flowering plants, starting with the growth of a pollen tube and ending with the fusion of nuclei. Powerpoint contains exam questions.

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 20 slides covering The organisation of cells By the end of the powerpoint students would have covered: -How the cells of multicellular organisms are organised into tissues. -How the tissues are organised into organs. -How the organs are organised into organ systems. Powerpoint contains exam questions

Designed for the new specification International A-level edexcel course but can be modified for other exam boards. 18 slides covering Prokaryotic cells By the end of the powerpoint students would have covered: -The ultrastructure of Prokaryotic cells. -Understand the function organelles in Prokaryotic cells Powerpoint contains a exam style question