Biology Revision Finals - Paper 1 Questions With 100%Verified Solutions | UPDATED

Biology Revision Finals - Paper 1 Questions With 100%Verified Solutions | UPDATED How do you calculate magnification? magnification = image size/actual size What are prokaryotic cell? Cells with no nucleus What characteristics do prokaryotic cells have? - Single celled - No nucleus - single loop of DNA - Plasmids - Smaller than eukaryotic cells Animal and plant cells, similarities and differences: Similarities, and differenced between bacteria, plant, and animal cells: Specialised cells, and their functions/adaptations: What Is a light microscope? A microscope that uses visible light and lenses What Is an electron microscope? electrons shoot through the cells to create an image Differences between electron, and light microscopes: What is diffusion? The movement of particles from an area of high concentration to an area of low concentration How to particles move during diffusion? Down a concentration gradient - high to low Is energy required for diffusion? No, it is a passive process Examples of diffusion: - The smell of perfumes/Incense Sticks - Dipping the tea bags in hot water will diffuse the tea in hot water - Small dust particles or smoke diffuse into the air and cause air pollution What is osmosis? diffusion of water across a semi permeable membrane How do the particles move during osmosis? low to high solute concentration Is energy required for osmosis? No, it is passive process Example of osmosis: soaking a raisin in water - It should swell up a little, this is because the water moves from where it is in high concentration ( the water ) into the raisins which have a low water concentration What is active transport? movement of molecules into or out of a cell How do particles move during active transport? against concentration gradient - low to high concentration Is energy required for active transport? yes - energy released by respiration Example of active transport: Ions moving from soil into plant roots What factors effect rate of diffusion? Different concentration - Steep = Faster diffusion rate Temperature - Higher temp = Faster diffusion rate Surface area of membrane - Larger membrane surface area = Faster diffusion rate What adaptations do single celled organisms have for exchanging substances? Large surface area to volume ratio, meaning enough molecules can be transported What adaptations do multi-cellular organisms have for exchanging substances? Small surface area to volume ratio, therefore they need a specialised organ system and cells to allow substantial molecule transport Cell transport in different parts of body/ plants/ animals: What are the five levels of organisation in living organisms? Acronym: