AQA A Level Biology 4/5/6mark Questions | Strategies Review Of Key Quizzes With 100% Verified Answers | Latest Update 2026 | 2027 (Rated Grade A+) Quiz_________________? 1 (Simple / facilitated) diffusion from high to low concentration / down con

AQA A Level Biology 4/5/6mark Questions | Strategies Review Of Key Quizzes With 100% Verified Answers | Latest Update 2026 | 2027 (Rated Grade A+) Quiz_________________? 1 (Simple / facilitated) diffusion from high to low concentration / down concentration gradient; 2 Small / non-polar / lipid-soluble molecules pass via phospholipids / bilayer; OR Large / polar / water-soluble molecules go through proteins; 3 Water moves by osmosis / from high water potential to low water potential / from less to more negative water potential; 4 Active transport is movement from low to high concentration / against concentration gradient; 5 Active transport / facilitated diffusion involves proteins/carriers; 6 Active transport requires energy / ATP; 7 Ref. to Na+ / glucose co-transport; - Answer Many different substances enter and leave a cell by crossing its cell surface membrane. Describe how substances can cross a cell surface membrane. (5) Quiz_________________? 1 Active site (of enzyme) has particular shape; 2 (Into which) substrate molecule fits / binds; 3 Appropriate reference linking induced fit and shape; 4 (Competitive inhibitor) has similar shape to substrate; 5 Also fits active sites; 6 Prevents substrate access; 7 (Non-competitive inhibitor) fits at site other than active site; 8 Distorting shape of active site / enzyme; 6 Prevents substrate access; (award once only) 9 Two types identified as competitive and non-competitive; - Answer Describe how molecular shape is important in explaining the way in which enzymes may be affected by inhibitors. (6) Quiz_________________? 1 each enzyme / protein has specific primary structure / amino acid sequence; 2 folds in a particular way / has particular tertiary structure giving an active site with a unique structure; 3 shape of active site complementary to / will only fit that of substrate; maximum of three marks for inhibition, points 5 - 8 4 inhibitor fits at site on the enzyme other than active site; 5 distorts active site; 6 so substrate will no longer fit / form enzyme-substrate complex - Answer Use your knowledge of protein structure to explain why enzymes are specific and may be affected by non-competitive inhibitors. (5) Quiz_________________? 1 Many alveoli / alveoli walls folded provide a large surface area; 2 Many capillaries provide a large surface area; 3 (So) fast diffusion; ________________________________________________ 4 Alveoli or capillary walls / epithelium / lining are thin / short distance between alveoli and blood; 5 Flattened / squamous epithelium; 6 (So) short diffusion distance / pathway; 7 (So) fast diffusion; ________________________________________________ 8 Ventilation / circulation; 9 Maintains a diffusion / concentration gradient; 10 (So) fast diffusion; - Answer Describe and explain how the lungs are adapted to allow rapid exchange of oxygen between air in the alveoli and blood in the capillaries around them. (5) Quiz_________________? 1 Prokaryotic cells do not have a nucleus / have genetic material in cytoplasm; 2 DNA in loop / ring; 3 Not associated with proteins / do not have chromosomes / chromatin / do not divide by mitosis; 4 Smaller ribosomes; 5 No membrane-bound organelles; 6 Such as mitochondria / lysosomes / endoplasmic reticulum / Golgi / chloroplasts; 7 Prokaryotic cells may have mesosomes; 8 Prokaryotic cells smaller; 9 May be enclosed by capsule; - Answer The bacteria in the intestine are prokaryotic cells. The epithelial cells which line the small intestine are eukaryotic cells. Describe the ways in which prokaryotic cells and eukaryotic cells differ. (6) Quiz_________________? 1 Some proteins pass right through membrane; 2 Some proteins associated with one layer; 3 Involved in facilitated diffusion; 4 Involved in active transport; 5 Proteins act as carriers; 6 Carrier changes shape / position; 7 Proteins form channels / pores; 8 Protein allows passage of water soluble molecules / charged particles / correct named example; - Answer Describe how proteins are arranged in a plasma membrane and the part they play in transporting substances into and out of cells. (6) Quiz_________________? 1 TEM uses (beam of) electrons; 2 These have short wavelength; 3 Allow high resolution/greater resolution/Allow more detail to be seen/greater useful magnification; 4 Electrons scattered (by molecules in air); 5 Vacuum established; 6 Cannot examine living cells; 7 Lots of preparation/procedures used in preparing specimens/ fixing/staining/sectioning; 8 May alter appearance/result in artefacts; - Answer Skin cells may be studied with a transmission electron microscope or an optical microscope. Explain the advantages and limitations of using a transmission electron microscope to study cells. (6) Quiz_________________? 1. (At source) sucrose is actively (transported) into the phloem/sieve element/tube; 2. By companion/transfer cells; 3. Lowers water potential in phloem/sieve element/tube and water enters by osmosis; 4. (Produces) high (hydrostatic) pressure; 5. Mass flow/transport towards sink/roots/storage tissue; 6. At sink/roots sugars are removed/unloaded; - Answer Describe the processes involved in the transport of sugars in plant stems. (5)