Biology

Animal cell organelles and what they do

Plant cell organelles and what they do

Bacterial cell structure (prokaryotes) vs eukaryotes

Comparing animal, plant and bacterial cells

Specialised cells and how structure links to function

Levels of organisation in multicellular organisms (cells → tissues → organs → systems)

Using SI units and prefixes in biology (milli, micro, nano, pico)

Estimating cell size and scale (orders of magnitude)

Light microscopes: uses, limits and what you can see

Electron microscopes: why they give more detail

Core Practical: Using a microscope to observe specimens and produce labelled scientific drawings

Calculating magnification, image size and real size

Using scale bars correctly

Enzymes as biological catalysts

The active site model (lock-and-key / induced fit idea at GCSE level)

Enzyme specificity (why one enzyme fits one substrate)

Effects of temperature on enzyme activity

Effects of pH on enzyme activity

Effects of substrate concentration on enzyme activity

Core Practical: Investigating the effect of pH on enzyme activity

Interpreting enzyme graphs and identifying optimum conditions

Calculating rates in enzyme experiments

Diffusion: definition and examples in cells

Factors affecting rate of diffusion (concentration gradient, surface area, distance, temperature)

Osmosis: definition and why it’s special

Osmosis in animal vs plant cells (turgid, plasmolysed, lysed)

Active transport: definition and where cells use it

Comparing diffusion, osmosis and active transport

Core Practical: Investigating osmosis in potato cylinders

Calculating percentage change in mass for osmosis data

Food tests: starch (iodine)

Food tests: reducing sugars (Benedict’s)

Food tests: proteins (biuret)

Food tests: fats (ethanol emulsion test)

Core Practical: Using chemical reagents to identify biological molecules

Energy content in food (simple calorimetry) and evaluating limitations

The cell cycle overview (growth, DNA replication, division)

Interphase: what happens and why it matters

Mitosis stage-by-stage: prophase

Mitosis stage-by-stage: metaphase

Mitosis stage-by-stage: anaphase

Mitosis stage-by-stage: telophase

Cytokinesis and forming daughter cells

Chromosomes, DNA and why daughter cells are genetically identical

Why mitosis is needed for growth and repair

Mitosis in asexual reproduction

Cancer as uncontrolled cell division

Growth in animals: cell division and differentiation

Growth in plants: cell division, elongation and differentiation

Cell differentiation and specialised cells

Using percentile charts to monitor human growth

Embryonic stem cells: what they are and what they can do

Adult stem cells and plant meristems

Stem cells in medicine: potential benefits

Stem cells in medicine: risks and ethical issues

Brain regions: cerebrum, cerebellum and medulla oblongata

CT scans: how they help study the brain

PET scans: how they help study brain function

Limits of treating brain and nervous system damage (spinal injuries, brain tumours)

Neurones: sensory, relay and motor (structures and roles)

Synapses and neurotransmitters (how signals cross gaps)

The reflex arc step-by-step

The eye: cornea and lens (focusing)

The eye: iris and pupil (controlling light entry)

The eye: retina, rod cells and cone cells

Eye defects: cataracts

Eye defects: long-sightedness and short-sightedness

Eye defects: colour blindness

Correcting vision defects (lenses and cataract treatment)

Asexual reproduction: advantages and disadvantages

Sexual reproduction: advantages and disadvantages

Meiosis: what it produces and why it creates variation

Haploid vs diploid and what gametes are

DNA as a polymer and why it’s called a polymer

The double helix and complementary base pairing

Nucleotides: sugar-phosphate backbone and bases

Genome vs gene (clear definitions)

Extracting DNA from fruit (method and why each step works)

The genetic code: base order → amino acid order

Protein folding and why shape matters (enzyme shape)

Transcription: making mRNA from DNA

Translation: using mRNA at ribosomes to build proteins

Codons and how triplets code for amino acids

tRNA and bringing amino acids to ribosomes

Non-coding DNA variants: changing how much protein is made

Coding DNA variants: changing amino acid sequence and protein function

Gregor Mendel’s work and why it was hard to accept at the time

Alleles as the reason inherited characteristics differ

Key inheritance terms (chromosome, gene, allele, genotype, phenotype, etc.)

Monohybrid crosses using genetic diagrams

Punnett squares: predicting offspring genotypes and phenotypes

Pedigree diagrams: tracking inheritance in families

Sex determination (XX/XY) using genetic diagrams

Calculating inheritance outcomes (ratios, percentages, probability)

ABO blood groups: codominance and multiple alleles

Sex-linked genetic disorders: how inheritance works

Polygenic inheritance (why most traits aren’t single-gene)

Causes of variation: genetic vs environmental

Human Genome Project: outcomes and medical applications

Genetic variation in populations and mutation as the source

Mutation effects: no effect, small effect, rare large effects

Darwin and Wallace: what they contributed and why it mattered

Natural selection: variation within populations

Natural selection: competition and selection pressures

Natural selection: survival and reproduction (fitness)

Natural selection: inheritance and how traits spread

Resistant organisms as evidence for evolution (antibiotic resistance)

Fossil evidence for human evolution: Ardi

Fossil evidence for human evolution: Lucy

Fossil evidence for human evolution: Leakey’s 1.6 million-year-old fossils

Evidence from stone tools: how tools changed over time

Dating stone tools using their environment (context evidence)

Pentadactyl limbs as evidence for evolution (homologous structures)

Classification: why genetic analysis supports three domains

Selective breeding: how humans change populations

Tissue culture: how it works and why it’s useful

Tissue culture in medical research and plant breeding

Genetic engineering: what it means (changing the genome)

Genetic engineering: restriction enzymes and cutting DNA

Genetic engineering: sticky ends and matching DNA fragments

Genetic engineering: ligase and joining DNA

Genetic engineering: vectors and transferring genes

GM crops example: Bt gene for insect resistance

Pros and cons of GM organisms (including ethics)

Fertilisers: boosting yields and potential drawbacks

Biological control: how it works and risks

Weighing benefits and risks of selective breeding and genetic engineering (agriculture + medicine)

Health as physical, mental and social wellbeing (WHO definition in context)

Communicable vs non-communicable disease

How one disease can increase susceptibility to others

Pathogens: viruses, bacteria, fungi and protists

Cholera: cause, symptoms and transmission route

Tuberculosis: cause, symptoms and airborne spread

Chalara ash dieback: impact and spread

Malaria: protist disease and vector transmission

HIV: effect on immune system and AIDS

Stomach ulcers and Helicobacter (separate science)

Ebola: key features and spread via body fluids (separate science)

Reducing spread: hygiene, sanitation, isolation and vaccination (applied to examples)

Viral lifecycles: lytic pathway

Viral lifecycles: lysogenic pathway

STIs: how chlamydia spreads and how to reduce spread

STIs: HIV spread and prevention strategies

Plant defences: physical barriers (cuticle, cell wall)

Plant defences: chemical defences and medicinal uses

Detecting plant disease: field observation and diagnostic testing

Human physical barriers: skin, mucus and cilia

Human chemical defences: lysozyme and stomach acid

Specific immune response: antigens and antibody production

Memory lymphocytes and the secondary immune response

Vaccination using inactive pathogens (how it builds immunity)

Immunisation: advantages, disadvantages and herd immunity

Why antibiotics treat bacterial infections but not viral infections

Aseptic technique in culturing microorganisms (incl. autoclaves and sterile tools)

Core Practical: Effects of antiseptics/antibiotics/plant extracts on microbial cultures

Measuring inhibition zones and calculating areas (πr²)

Stages of developing new medicines (discovery → trials)

Preclinical testing vs clinical testing (what each checks)

Producing monoclonal antibodies (lymphocytes → hybridoma)

Uses of monoclonal antibodies: pregnancy tests

Uses of monoclonal antibodies: diagnosis and targeted treatment

Advantages of monoclonals vs drugs/radiotherapy (targeting)

Non-communicable disease as multi-factor (genes + lifestyle + environment)

Lifestyle: diet and exercise links to obesity and malnutrition (BMI)

Lifestyle: alcohol and liver disease

Lifestyle: smoking and cardiovascular disease

Treating cardiovascular disease: medication

Treating cardiovascular disease: surgery

Treating cardiovascular disease: lifestyle change (evaluation)

Photosynthetic organisms as producers and the start of biomass

Photosynthesis word equation and symbol equation

Photosynthesis as an endothermic reaction (energy in)

Limiting factors: light intensity

Limiting factors: carbon dioxide concentration

Limiting factors: temperature

Interactions between limiting factors (shifting the limiting factor)

Core Practical: Effect of light intensity on photosynthesis rate

Inverse square law and light intensity vs distance (applied to photosynthesis)

Root hair cells: adaptations for absorption

Xylem: structure and transporting water/mineral ions

Phloem: structure and transporting sucrose (needs energy)

Transpiration: movement of water through the plant

Stomata and guard cells: structure and function

Translocation: moving sugars around the plant

Leaf structure: palisade layer, spongy mesophyll and air spaces

Leaf structure: stomata distribution and gas exchange

Leaf structure: chloroplasts and light capture

Environmental factors affecting water uptake (light, wind, temperature)

Rate calculations for transpiration (interpreting change over time)

Plant adaptations to extreme environments (leaf size/shape, cuticle, stomata)

Auxins and control of growth

Phototropism: how auxin causes shoots to bend to light

Gravitropism: how auxin causes roots/shoots responses

Commercial uses of auxins (weedkillers, rooting powders)

Commercial uses of gibberellins (germination, flowering, seedless fruit)

Commercial uses of ethene (fruit ripening)

Endocrine system overview: hormones and target organs

Key endocrine glands (pituitary, thyroid, pancreas, adrenal, ovaries, testes)

Adrenaline and the fight-or-flight response

Adrenaline effects: heart rate, blood pressure and blood flow to muscles

Adrenaline effects: raising blood glucose via glycogen → glucose

Thyroxine and metabolic rate

Negative feedback control using thyroxine (TRH, TSH, thyroxine loop)

Menstrual cycle stages (uterus lining changes)

Oestrogen: roles in the menstrual cycle

Progesterone: roles in the menstrual cycle

FSH and LH: roles and ovulation

Hormone interactions controlling menstruation and uterus lining

Hormonal contraception: how it prevents pregnancy

Barrier contraception: how it prevents pregnancy

Evaluating hormonal vs barrier contraception

Fertility treatment hormones: IVF steps overview

Clomifene therapy: how it works (stimulating ovulation)

Why a constant internal environment matters

Homeostasis overview: thermoregulation and osmoregulation

Thermoregulation: how temperature affects enzymes

Skin structure for thermoregulation (dermis, epidermis)

Hypothalamus as the thermoregulatory control centre

Thermoregulation responses: shivering

Thermoregulation responses: vasoconstriction and vasodilation

Blood glucose control: insulin role

Blood glucose control: glucagon role

Type 1 diabetes: cause and control methods

Type 2 diabetes: cause and control methods

BMI and waist:hip calculations (linking data to diabetes risk)

Evaluating the correlation between body mass and type 2 diabetes

Urinary system structure (kidneys, ureters, bladder, urethra)

Nephron structure overview (Bowman’s capsule to collecting duct)

Filtration at the glomerulus and Bowman’s capsule

Selective reabsorption of glucose

Water reabsorption and balancing water levels

ADH and collecting duct permeability

Kidney failure treatments: dialysis vs transplant

Urea formation from excess amino acids in the liver

Why organisms need transport systems (O₂, CO₂, nutrients, ions, water, urea)

Exchange surfaces: what they are and why they’re needed

Surface area to volume ratio and its consequences

Alveoli adaptations for diffusion (large SA, short distance, blood supply)

Diffusion rate factors in exchange (surface area, gradient, distance)

Using Fick’s law to calculate diffusion rate (separate science)

Blood components: red blood cells and oxygen transport

Blood components: white blood cells (phagocytes and lymphocytes)

Blood components: plasma and what it carries

Blood components: platelets and clotting

Blood vessels: arteries structure and function

Blood vessels: veins structure and function

Blood vessels: capillaries structure and function

Heart structure: chambers and valves

Double circulatory system: pulmonary vs systemic

Why ventricle walls differ in thickness

Cellular respiration: why cells need it

Aerobic respiration: reactants, products and energy release

Anaerobic respiration: how it differs and when it happens

Comparing aerobic and anaerobic respiration

Core Practical: Investigating respiration rate in living organisms

Heart rate, stroke volume and cardiac output calculations

Interpreting exercise data for breathing rate and heart rate

Levels of organisation: organism to ecosystem

Abiotic factors affecting communities (temperature, light, water, pollutants)

Biotic factors affecting communities (competition, predation)

Interdependence in communities

Parasitism and mutualism (with clear examples)

Core Practical: Fieldwork using quadrats and belt transects

Choosing an appropriate sampling method (random vs along a gradient)

Calculating means from field data

Estimating population size or abundance from quadrat data

Using transect results to describe distribution patterns

Energy in ecosystems: producers, consumers and decomposers

Energy transfer losses at each trophic level (less useful forms)

Pyramids of biomass: what they show and why shapes differ

Calculating efficiency of energy transfer between trophic levels

Human impacts: fish farming (benefits and harms)

Human impacts: non-indigenous species and biodiversity

Human impacts: eutrophication causes and effects

Why biodiversity matters (local and global)

Conservation strategies and reforestation impacts

Food security: population growth and demand

Food security: meat consumption and land use

Food security: pests, pathogens and environmental change

Sustainability issues (biofuels, cost of inputs)

Material cycles overview (abiotic ↔ biotic)

Carbon cycle processes and the role of decomposers

Water cycle processes and potable water production (incl. desalination)

Nitrogen cycle: nitrates, bacteria and plant uptake

Farming strategies: fertilisers and crop rotation (linked to nitrates)

Indicator species for water pollution (clean vs polluted water)

Indicator species for air quality (lichens, blackspot fungus)

Decomposition: what it is and why it matters

Decomposition rate factors: temperature, water content, oxygen

Food preservation explained using decomposition factors

Composting explained using decomposition factors

Calculating rate changes in decay of biological material