GCSE Biology exam with correct answers 2024

What process do plants use to move mineral ions into root cells? - answer-Active transport Describe how water moves from roots to the leaves. - answer-By transpiration stream in xylem. What advantage to a plant does having very few stomata on the upper surface of the leaf have? - answer-Less water lost so it will not wilt. Why should tools used to handle plants with TMV be washed afterwards? - answer-To prevent the virus spreading. How can scientists use a plant with a TMV-resistant gene to create more plants resistant to TMV? - answer-They can take stem cells from the meristem. How would you test for the presence of glucose in a fruit? - answer-Heat a sample of the fruit and add a few drops of Benedict's solution. Glucose will turn the solution from BLUE to ORANGE. TMV causes plants to produce less chlorophyll. This causes leaf discolouration. Explain why plants with TMV have stunted growth. - answer-Less photosynthesis is carried out, therefore less glucose is made so there is less energy for growth because glucose is needed for making amino acids. How does the human body prevent the entry of microbes? - answer-Acid in the stomach kills pathogens in food. Skin forms a barrier / produces antimicrobial secretions. Hairs in the nose trap particles, which may contain pathogens. Trachea/bronchi has mucus which traps pathogens. Bronchi have cilia which waft mucus to throat to be swallowed. Describe how glucose from the small intestine is moved to a muscle cell. - answer-Glucose is absorbed by diffusion into the bloodstream, then blood delivers the glucose to muscles in capillaries. Describe the test you would use to find out if protein is present in food. - answer-Add Biuret reagent to the food sample. A purple colour shows that protein is present.