Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.6 - Understand the names given to different trophic levels, including producers, primary, secondary and tertiary consumers and decomposers. Specification Point 4.7 - Understand the concepts of food chains, food webs, pyramids of number, pyramids of biomass and pyramids of energy transfer. Specification Point 4.8 - Understand the transfer of substances and energy along a food chain. Specification Point 4.9 - Understand why only about 10% of energy is transferred from one trophic level to the next. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.5 - Understand how abiotic and biotic factors affect the population size and distribution of organism. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.12 -Understand the biological consequences of pollution of air by sulfur dioxide and carbon monoxide. Specification Point 4.13 - Understand that water vapour, carbon dioxide, nitrous oxide, methane and CFCs are greenhouse gases. Specification Point 4.14 - Understand how human activities contribute to greenhouse gases. Specification Point 4.15- Understand how an increase in greenhouse gases results in an enhanced greenhouse effect and that this may lead to global warming and its consequences. Specification Point 4.16 - Understand the biological consequences of pollution of water by sewage. Specification Point 4.17 - Understand the biological consequences of eutrophication caused by leached minerals from fertilizer. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.11B - Describe the stages in the nitrogen cycle, including the roles of nitrogen fixing bacteria, decomposers, nitrifying bacteria and denitrifying bacteria. Complete set of Chapter 6 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 4.10 - Describe the stages in the carbon cycle, including respiration, photosynthesis, decomposition and combustion. Complete set of Chapter 6 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 5.10 - Understand how selective breeding can develop plants with desired characteristics. Specification Point 5.11 - Understand how selective breeding can develop animals with desired characteristics. Complete set of Chapter 7 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.93 - Describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.90 - Describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object. Specification Point 2.91 - Describe the structure and function of the eye as a receptor. Specification Point 2.92 - Understand the function of the eye in focusing on near and distant objects, and in responding to changes in light intensity. Complete set of Chapter 4 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.1 - Understand the differences between sexual and asexual reproduction. Specification Point 3.2 - Understand that fertilization involves the fusion of a male and female gamete to produce a zygote that undergoes cell division and develops into an embryo. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 2.94 - Understand the sources, roles and effects of the following hormones: adrenaline, insulin, testosterone, progesterone and oestrogen. Complete set of Chapter 4 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 3.8 - 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 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.10B - Understand the roles of FSH and LH in the menstrual cycle. Complete set of Chapter 5 Lectures are available.

Powerpoint lecture 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 Lectures are available.

Powerpoint lecture covering the following in a modern, concise format: Specification Point 3.19 - Understand how genes exist in alternative forms called alleles which give rise to differences in inherited characteristics. Specification Point 3.20 - Understand the meaning of the terms: dominant, recessive, homozygous, heterozygous, phenotype, and genotype. Specification Point 3.21B - Understand the meaning of the term codominance. 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.