BiologyQ&A by dot point

Animal and plant cell structures and their functions, examples of specialised cells and their adaptations, the levels of organisation from cell to organism, and using a light microscope including magnification calculations.

Enzymes as biological catalysts, the lock and key model and the active site, how temperature and pH affect enzyme activity including denaturing, and investigating enzyme activity experimentally.

The structure of a leaf and how its tissues are adapted for photosynthesis and gas exchange, the role of stomata and guard cells, and how gases diffuse into and out of the leaf.

The components of a balanced diet and their sources and functions, the consequences of an unbalanced diet, the energy content of food, and the chemical food tests for starch, reducing sugar, protein and fat.

The word and symbol equations for photosynthesis, the role of chlorophyll and chloroplasts, the limiting factors of light intensity, carbon dioxide concentration and temperature, and experiments to investigate the rate of photosynthesis.

The organs of the digestive system and their functions, the digestive enzymes amylase, protease and lipase with their substrates and products, the role of bile, and absorption in the villi of the small intestine.

The terms population, community, habitat and ecosystem, the difference between producers, consumers and decomposers, food chains and food webs, and the interdependence of organisms including predator and prey relationships.

How energy from the Sun flows through food chains, why energy is lost at each trophic level, pyramids of numbers and biomass, and calculating the efficiency of energy transfer between trophic levels.

The causes and effects of pollution including water and air pollution, the use of indicator species to monitor pollution, the consequences of habitat destruction and deforestation, and conservation measures to protect biodiversity.

The carbon cycle including photosynthesis, respiration, combustion and decomposition, and the nitrogen cycle including the roles of decomposers and nitrogen-fixing, nitrifying and denitrifying bacteria.

Using quadrats to estimate abundance and percentage cover, using transects to study how distribution changes across a habitat, the meaning of biodiversity, and calculating means and population estimates from sampling data.

The relationship between the nucleus, chromosomes, genes and DNA, the structure of DNA as a double helix with complementary base pairs, the human chromosome number, and how genes control the characteristics of an organism.

Mitosis as cell division producing two genetically identical cells for growth and repair, meiosis as division producing four genetically different gametes with half the chromosome number, and why meiosis creates variation.

The terms gene, allele, dominant, recessive, homozygous, heterozygous, genotype and phenotype, and using Punnett squares to predict the ratios and probabilities of offspring in a monohybrid cross.

How the base sequence of a gene codes for the order of amino acids in a protein, the roles of transcription and translation, the part played by mRNA and ribosomes, and how mutations can change a protein.

How the X and Y sex chromosomes determine sex, using a genetic cross to show the equal chance of a boy or girl, and how genetic disorders such as cystic fibrosis are inherited from carrier parents.

Pathogens as disease-causing microorganisms and how they spread, the body's first-line defences such as the skin, and the role of white blood cells in defending the body by phagocytosis and antibody production.

How antibiotics treat bacterial infections but not viral ones, the problem of antibiotic resistance and how to reduce it, the difference between medical and recreational drugs, and the effects of alcohol and tobacco on health.

The main types of microorganism (bacteria, viruses and fungi), the conditions microorganisms need to grow, their useful roles in food production such as yoghurt and bread, and the use of microorganisms in biotechnology including aseptic technique.

How the immune system produces memory cells for long-term immunity, how a vaccine uses a dead or weakened pathogen to make the body immune, and how vaccination protects individuals and populations (herd immunity).

The components of the blood and their functions, the structure of the heart with its chambers and valves, the path of blood through the heart, and how the heartbeat pumps blood around the double circulation.

Hormones as chemical messengers carried in the blood, the control of blood glucose by insulin, the difference between type 1 and type 2 diabetes, the role of adrenaline, and the difference between nervous and hormonal control.

Osmosis as the movement of water across a partially permeable membrane, turgid, flaccid and plasmolysed plant cells, the roles of xylem and phloem, water uptake by root hair cells, and transpiration and the factors affecting it.

The double circulatory system, the structure and function of arteries, veins and capillaries, how each blood vessel is adapted to its job, and the effect of lifestyle on the circulatory system including coronary heart disease.

The central nervous system, sensory, relay and motor neurones, the reflex arc as a fast automatic response, the structure and function of the eye, and how the eye focuses light and adjusts to light intensity.

The structure of the human respiratory system, the mechanism of breathing in and out, gas exchange in the alveoli and their adaptations, the difference between breathing and respiration, and the effects of smoking.

How genetic engineering transfers a gene from one organism to another using enzymes and vectors, examples such as insulin-producing bacteria and GM crops, methods of cloning, and the benefits and ethical issues.

The theory of evolution by natural selection, how variation, competition and survival of the best-adapted lead to a change in a species over time, antibiotic resistance as an example, and the evidence from fossils.

How selective breeding chooses parents with desired characteristics over many generations, examples in crops and farm animals, and the benefits and risks including reduced variation and inbreeding.

The male and female reproductive systems, the hormones oestrogen and progesterone in the menstrual cycle, the role of FSH and LH, and how hormones are used in contraception and fertility treatment such as IVF.

The difference between continuous and discontinuous variation, the genetic and environmental causes of variation, how variation data is presented, and the role of mutation in producing new variation.