GCSE Biology: Past Paper Questions and Answers (AQA)

GCSE Biology: Past Paper Questions and Answers (AQA) well explained with guaranteed success. What process do plants use to move mineral ions into root cells? - correct answersActive transport Describe how water moves from roots to the leaves. - correct answersBy transpiration stream in xylem. What advantage to a plant does having very few stomata on the upper surface of the leaf have? - correct answersLess water lost so it will not wilt. Why should tools used to handle plants with TMV be washed afterwards? - correct answersTo prevent the virus spreading. How can scientists use a plant with a TMV-resistant gene to create more plants resistant to TMV? - correct answersThey can take stem cells from the meristem. How would you test for the presence of glucose in a fruit? - correct answersHeat 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. - correct answersLess 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? - correct answersAcid 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. - correct answersGlucose 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. - correct answersAdd Biuret reagent to the food sample. A purple colour shows that protein is present.