Powerpoint lecture and associated PDF worksheet covering the following in a modern, concise format: Specification Point 3.16B - Describe a DNA molecule as two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with thymine (T), and cytosine © with guanine (G). Specification Point 3.17B - Understand that an RNA molecule is single stranded and contains uracil (U) instead of thymine (T). Specification Point 3.18B - Describe the stages of protein synthesis including transcription and translation, including the role of mRNA, ribosomes, tRNA, codons and anticodons. Complete set of Chapter 5 Lessons are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 40 - Evolution. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 3.38 - Explain Darwin’s theory of evolution by natural selection. Specification Point 3.39 - Understand how resistance to antibiotics can increase in bacterial populations, and appreciate how such an increase can lead to infections being difficult to control. Complete set of Chapter 5 Worksheets are available.

Companion PDF worksheet for Edexcel IGCSE Biology Lecture 38 - Human Reproduction and the Menstrual Cycle. Contains short answer questions, an activity requiring lateral thinking and exam-style questions. Specification Point 3.8 - Understand how the structure of the male and female reproductive systems are adapted for their functions. Specification Point 3.9 - Understand the roles of oestrogen and progesterone in the menstrual cycle. Complete set of Chapter 5 Worksheets are available.

Powerpoint lecture and associated PDF worksheet covering the following in a modern, concise format: Specification Point 3.11 - Describe the role of the placenta in the nutrition of the developing embryo. Specification Point 3.12 - Understand how the developing embryo is protected by amniotic fluid. Specification Point 3.13 - Understand the roles of oestrogen and testosterone in the development of secondary sexual characteristics. Complete set of Chapter 5 Lessons 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 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 3.8.3 - Using genome projects. Specification Point 3.8.4.1 - Recombinant DNA technology. Complete set of Chapter 8 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.15 - Understand the processes of diffusion, osmosis and active transport by which substances move into and out of cells. Specification Point 2.16 - Understand how factors affect the rate of movement of substances into and out of cells, including the effects of surface area to volume ratio, distance, temperature and concentration gradient. Specification Point 2.17 - Practical: Investigate diffusion and osmosis using living and non-living systems. Complete set of Chapter 1 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.1 -Describe the level of organisation in organisms: organelles, cells, tissues, organs and organ systems. Specification Point 2.2/2.3 - Describe the structures and functions of the cell’s organelles, including the nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplast, ribosome and vacuole. Complete set of Chapter 1 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.48 - Explain how alveoli are adapted for gas exchange by diffusion between air in the lungs and blood in capillaries. Specification Point 2.49 - Understand the biological consequences of smoking in relation to the lungs and the circulatory system, including coronary heart disease. Specification Point 2.50 - Practical: Investigate breathing in humans, including the release of carbon dioxide and the effect of exercise. Complete set of Chapter 3 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.83 - Understand that plants respond to stimuli. Specification Point 2.84 - Describe the geotropic and phototropic responses of roots and stems. Specification Point 2.85 - Understand the role of auxin in the phototropic response of stems. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.72B - Understand how the kidney carries out its roles of excretion and osmoregulation. Specification Point 2.73B - Describe the structure of the urinary system, including the kidneys, ureters, bladder and urethra. Specification Point 2.74B - Describe the structure of a nephron, including the Bowman’s capsule and glomerulus, convoluted tubules, loop of Henle and collecting duct. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.35B - Understand how a change in DNA can affect the phenotype by altering the sequence of amino acids in a protein. Specification Point 3.36B - Understand how most genetic mutations have no effect on the phenotype, some have a small effect and rarely do they have a significant effect. Specification Point 3.37B - Understand that the incidence of mutations can be increased by exposure to ionising radiation (for example, gamma rays, x-rays and ultraviolet rays) and some chemical mutagens (for example, chemicals in tobacco). Complete set of Chapter 5 Lectures are available.

Powerpoint lecture 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 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.95B - Understand the sources, roles and effects of the following hormones: ADH, FSH and LH. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.11 - Describe the role of the placenta in the nutrition of the developing embryo. Specification Point 3.12 - Understand how the developing embryo is protected by amniotic fluid. Specification Point 3.13 - Understand the roles of oestrogen and testosterone in the development of secondary sexual characteristics. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.28 - Understand how division of a diploid cell by mitosis produces two cells that contain identical sets of chromosomes. Specification Point 3.29 - Understand that mitosis occurs during growth, repair, cloning and asexual reproduction. Specification Point 3.30 - Understand how division of a cell by meiosis produces four cells, each with half the number of chromosomes, and that this results in the formation of genetically different haploid gametes. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture 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 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.21 - Describe the structure of the leaf and explain how it is adapted for photosynthesis. Specification Point 2.22 - Understand that plants require mineral ions for growth, and that magnesium ions are needed for chlorophyll and nitrate ions are needed for amino acids. Complete set of Chapter 2 Lectures are available.