Below is a list of the individual lessons within each topic of this GCSE biology course, with an outline of what each lesson covers.
Click on a lesson to get started, or click the ‘course navigation’ button above.
Cell Biology
Discovery of cells, and the definition the term “cell”; the differences between eukaryotic and prokaryotic cells; description of the relationships between the sub-cellular structures in prokaryotic and eukaryotic cells to their functions.
Definition of the terms tissue, organ, organ system, differentiation, specialisation; adaptations of specialised cells to their functions (e.g. sperm, ovum & ciliated epithelial cells).
The development, components & operation of optical & electron microscopes; orders of magnitude of size from milli- to picometres, and interconversion of units; calculation of object/image size & magnification.
Process of tissue culture & use in medical research & plant breeding; detailed description of aseptic technique for preparation of uncontaminated cultures; binary fission & calculation of size of bacterial populations.
Stages of cell cycle; mitosis; cell differentiation; stem cells (embryonic & adult stem cells in animals, meristem tissue in plants), their biological function & potential medical use (including ethical considerations).
Diffusion, osmosis & active transport across cell boundaries; significance of surface area to volume ratio; rate of diffusion & Fick’s law; examples to illustrate these principles.
Organisation in Biological Systems
Limitations of the size of cells & unicellular organisms due to surface area to volume ratio; hierarchical levels of organisation in biology with definitions of examples of specialised cells, tissues, organs, organ systems.
Structure and function of the major organs of the digestive system including oesophagus, stomach, and small & large intestines; definitions & distinctions between the terms digestion, absorption & assimilation.
Sites of production & action of digestive enzymes (e.g. amylase, proteases & lipases) in mammals, including their substrates & products; production and storage of bile, and its neutralising & emulsifying functions.
Overview of the methods used to test for a range of nutrients such as carbohydrates, lipids and proteins (to include: Benedict’s solution test for sugars, iodine test for starch, and Biuret reagent for protein.
Definition of “metabolism”; the role of enzymes as biochemical catalysts; relationship between enzyme activity, temperature and pH; lock & key and induced fit models; explanation of the denaturation of enzymes.
Structure & function of the heart; comparison of structures & functions of arteries, veins & capillaries; blood as a tissue composed of four parts, and the functions of these (plasma, red cells, white cells & platelets).
Structure & function of the human respiratory system; adaptations of alveolar gas exchange surface to maximise rate of diffusion; mechanism of ventilation (breathing) in humans.
Transpiration & water transport; translocation of sugars & assimilates; structure vs. function of epidermal, palisade & spongy mesophyll, xylem, phloem & meristem tissues; factors affecting rate of transpiration.
Metabolism, Health & Lifestyle
Health as a state of physical, mental & social wellbeing; ways diseases can interact (communicable vs. non-communicable, physical & mental illness), with examples; effect of exercise & diet on health and fitness.
Risk factors, pathology & treatment of cardiovascular diseases, including coronary heart disease, valve dysfunctions, and heart failure; evaluation of treatment by drugs, mechanical devices or transplant.
Alcohol & tobacco consumption & association with increased risk/incidence of diseases, including both qualitative description of pathology & quantitative interpretation of risk & incidence data.
Categorise illegal drugs (Classes A, B and C); describe & explain short-term & long-term effects of drug abuse, including heroin, cocaine, MDMA (ecstasy), barbiturates, LSD, amphetamine, cannabis & solvent abuse.
Cancer as a result of cellular changes which cause dysfunction of the processes which normally regulate cell division, leading to rapid and uncontrolled cell division; risk factors; malignant vs. benign tumours.
Infection & Response
Pathogens as microorganisms that cause disease (to include viruses, bacteria, protists or fungi); spread of infectious disease in animals & plants and how this can be prevented or reduced; viral “life-cycles”.
Non-specific defence systems & role of the immune system in defence against disease in humans; process by which antigens from pathogens cause production & release of specific antibodies; action of antibodies.
Overview of the use of drugs and other medical interventions to treat infectious diseases; explanation of the production and action of vaccines (in terms of immune system mechanism for immunisation) and antibiotics.
Process of discovery & development of potential new medicines, including pre-clinical stage (discovery, animal testing & patent application), clinical stage (small, medium & large scale trials) and post-market stage.
Overview of process for production of monoclonal antibodies (including production of hybridoma cells); use of monoclonal antibodies (e.g. pregnancy testing, diagnosis & imaging, drug & radiotherapy targeting).
Structure & Function of physical (cell walls, cuticle, bark), chemical (antibacterials, toxins) and mechanical (thorns, hairs, mimicry) adaptations of plants to resist infection and deter herbivorous animals.
In this lesson we review some examples of bacterial, viral and fungal pathogens which cause disease in plants, including the symptoms, mechanisms of tissue damage and treatments & precautions.
Bioenergetics
Photosynthesis & factors affecting its rate; use of glucose produced in photosynthesis for respiration or production of other nutrients; structure & function of leaves in relation to maximising rate of photosynthesis.
The main minerals required by plants and their functions in the organism; the deficiency diseases that result from plants lacking specific essential minerals/nutrients, and the signs of these deficiency diseases.
Overview of the processes of aerobic and anaerobic respiration and their significance in animals, plants and other organisms (e.g. yeast); overview of metabolism of glucose (including conversion to to other nutrients).
Responses to exercise, including changes in heart rate, breathing rate & breath volume related to increased rate of respiration; anaerobic respiration in muscles during exercise (including “oxygen debt” concept).
Experimental procedures for measuring the rates of respiration in simple organisms (e.g. small insects, germinating seeds, etc.); measurement & calculation of rate of photosynthesis from graphical or other data.
An overview of the experimental aspects of measuring the energy content of food using a calorimetric technique, including the calculation of energy content per unit dry mass from appropriate calorimetric data.
Homeostasis, Sensitivity & Response
General concept of homeostasis by negative feedback & significance in maintaining life; sequence of events involved in general scheme of homeostasis (stimulus, receptor, coordinator, effector, response) with examples.
An overview of the structure & function of the human nervous system in relation to the general scheme: stimulus, receptor, coordinator, effector, response; sensory & motor neurones; the reflex arc & reflex actions.
Identify parts of the human brain and describe their functions; explain the difficulties of investigating brain function, treating brain damage & disease; describe non-invasive techniques used to study the brain.
Structure & function of the eye and its constituent parts; explanation of the action of various structures in the eye in the processes of accommodation & adaptation; eye defects (myopia & hyperopia) and their correction.
Principles of human hormonal coordination & control (hormones, their transport in blood, endocrine glands & their secretions/functions, receptors); negative feedback; examples including thyroxine & adrenaline.
Role of receptors in skin & thermoregulatory centre of brain in core body temperature regulation by negative feedback; responses to changes in temp. (vasoconstriction & vasodilation, hairs, sweating, shivering, etc.).
Regulation of blood glucose concentration by negative feedback; role of pancreas, liver & muscle tissue in glucose regulation; role of hormones (insulin & glucagon); Types 1 & 2 diabetes (causes, pathology & treatment).
An overview of the structure & function of human excretory system; osmoregulation by negative feedback, including the process of ultrafiltration & selective reabsorption in nephrons & control via hormonal action (ADH).
An overview of the role of hormones in human reproduction with particular reference to the menstrual cycle, including repair & maintenance of uterine wall, ovulation & menstruation (FSH, oestrogen, LH & progesterone).
Control & coordination of plant growth & development, including the role of auxins in phototropisms & gravitropisms; effects of plant hormones (auxins, gibberellins & ethene); the use of plant hormones in agriculture.
Ineritance, Variation & Evolution
An overview of the relative advantages and disadvantages of sexual and asexual reproduction, with examples of organisms using either or both methods of reproduction from animal, plant, fungus and bacterial species.
The role of meiotic cell division in sexually reproducing organisms, including production of 4 daughter cells (genetically different haploid gametes); significance of meiosis in ensuring genetic variation in offspring.
Structure of DNA (nucleotide monomers, phosphodiester bonds, complementary base-pairing via hydrogen bonds); description of genome in terms of genes, chromosomes & DNA; significance of study of human genome.
Central dogma of molecular biology; encoding of information determining the primary structure of proteins (and therefore tertiary structure & function) in base sequences within genes; the stages in protein synthesis.
Significance of mutation in generating genetic & phenotypic diversity; genetic aspects of mutation in genes and resulting changes in phenotype (i.e. protein structure & function); effects of mutations in non-coding DNA.
Key terms (e.g. genes, alleles, dominant, recessive, homozygous, heterozygous); Mendel’s work in fundamental ideas of heredity; Punnett square; human sex determination; ABO blood groups; genetic disorders.
The significance & origins of variation in species, and the process of natural selection leading to speciation (evolution); work of Darwin & Wallace; factors which may contribute to the extinction of a species.
Classification by structure & characteristics (Linnaeus’ system & binomial nomenclature); how genetic analysis has led to the suggestion of the three domains rather than the five kingdoms classification method.
Selective breeding in agriculture & animal husbandry; stages in genetic engineering; tissue culture, embryonic & adult cell cloning; evaluating applications of these processes.
Ecology
Levels of organisation in an ecosystem; abiotic & biotic factors affecting communities; typical adaptations of organisms found in differing environments; importance of interdependence & competition in communities.
Overview of the sampling techniques in ecology, including practical aspects & analysis of data from such techniques in determining biodiversity & distribution of organisms.
Concept of the cycling of substances through abiotic and biotic components of ecosystems, to include the mechanisms involved in the carbon, water & nitrogen cycles; significance human activities to these cycles.
Significance & mechanisms of biological decay; influence of abiotic factors (e.g. availability of water & oxygen, and temperature) on the rate of decay; calculation of the rate of change of decay from appropriate data.
Impact of human activity & pollution on the biodiversity & distribution of organisms in ecosystems; pollutants & their effects; deforestation; methods to ameliorate negative human impact (e.g. conservation, recycling).
Overview of the human influence on climate change due to the production of greenhouse gases such as methane and carbon dioxide; the “greenhouse effect”; the ecological & biological consequences of “global warming”’.
Trophic levels & feeding relationships, and significance in the transfers of nutrients & energy in ecosystems; concept of biomass; construction & interpretation of pyramids of biomass; efficiency of biomass transfers.
Factors affecting levels of food security for humans; advantages & disadvantages of modern farming & fishing techniques; evaluation of bio-technical & agricultural solutions, including genetic modification.