Teacher License – Biology Complete Review Guide 2026–2027

4. Photosynthesis: carbon dioxide + water + light gives glucose + oxygen. The oxygen released comes from water, and the process takes place in chloroplasts (6.8.6, indicator 2).
5. Transpiration is the loss of water vapour from leaves, mostly through stomata controlled by guard cells. It pulls water up through the xylem (6.8.6, indicator 1).
6. Digestion is mechanical and chemical: salivary amylase starts starch digestion, stomach pepsin digests protein in acid, and most digestion and absorption occur in the small intestine. Bile from the liver breaks fat into small droplets (6.8.6, indicator 3).
7. Humans cannot digest cellulose because they lack the enzyme cellulase (6.8.6, indicator 3).
8. Gas exchange happens in the alveoli: oxygen enters the blood and carbon dioxide leaves. Air is drawn in when the diaphragm contracts. Birds have air sacs that give a one-way flow of air through the lungs (6.8.6, indicator 3).
9. Human circulation is double and the heart has four chambers. Arteries carry blood away from the heart, veins return it, and haemoglobin in red blood cells carries oxygen (6.8.6, indicator 3).
10. Excretion: the kidney filters blood and forms urine in nephrons, the liver removes harmful substances and converts ammonia to urea, the lungs expel carbon dioxide, and the skin excretes sweat (6.8.6, indicator 3).
11. The nervous and endocrine systems work together to maintain internal balance, often through negative feedback (6.8.6, indicator 4).
12. Hormone examples: insulin (pancreas) lowers blood glucose, glucagon raises it, thyroxine (thyroid) regulates metabolic rate, and adrenaline (adrenal gland) prepares the body for a rapid response (6.8.6, indicator 6).
13. Innate immunity is non-specific and includes skin, mucus, phagocytes, inflammation and fever. Acquired immunity is specific with memory and relies on B cells and T cells (6.8.7, indicator 1).
14. B cells differentiate into plasma cells that secrete antibodies, and some remain as memory cells. Helper T cells coordinate the response and cytotoxic T cells kill infected cells (6.8.7, indicator 1).
15. Active immunity: the body makes its own antibodies after an infection or a vaccine, and it lasts long. Passive immunity: the body receives ready-made antibodies (through the placenta, breast milk or an antiserum) and it lasts a short time (6.8.7, indicator 1).
16. A vaccine contains a weakened or killed pathogen, or part of one, so the body makes antibodies and memory cells without getting ill (6.8.7, indicator 2).
17. Pathogens include bacteria, viruses, fungi, protozoa and parasitic worms. They are controlled by hygiene, sterilisation, safe drinking water and vaccination, with antibiotics for bacteria only (6.8.7, indicator 3).
18. Inherited diseases come from changes in genes or chromosomes and pass from parents to children, such as sickle cell anaemia and cystic fibrosis, and colour blindness and haemophilia (X-linked recessive). Non-inherited diseases include infections, nutritional deficiencies and injuries (6.8.7, indicator 4).

Common mistakes in this chapter

• ✕ A vaccine gives artificial active immunity, not passive immunity, because the body makes its own antibodies. Passive immunity means receiving ready-made antibodies (from the mother or from an antiserum).
• ✕ Innate immunity is non-specific and has no memory. Acquired immunity is specific and remembers the antigen. Do not attribute immune memory to the skin or to phagocytes.
• ✕ Antibiotics act on bacteria and have no effect on viruses, so they do not treat influenza or the common cold.
• ✕ An antigen and an antibody are different things. The antigen is a foreign molecule that triggers the response. The antibody is a protein secreted by plasma cells (which come from B cells), not by T cells.
• ✕ An inherited disease is not passed on by infection; it comes from a change in genes or chromosomes. Equally, a condition present at birth is not always inherited.
• ✕ Breathing (gas exchange in the lungs) is different from cellular respiration (making ATP inside cells). Plants carry out cellular respiration day and night, not only photosynthesis.
• ✕ The light reactions in the thylakoids make ATP, NADPH and oxygen. Fixing carbon dioxide and building sugar happen in the stroma. Do not swap the location of the two stages.
• ✕ Hormones travel in the blood, so their effect is slower and lasts longer. Nerve impulses are faster and shorter-lived. A question about speed of response usually points to the nervous system.