In most plants there are many more stomata in the lower epidermis of a leaf than in the upper epidermis. Which statement gives the advantage of this to the plant?
The lower surface is cooler, so less water vapour is lost
The lower surface is shaded, so more carbon dioxide diffuses in
The upper surface is warmer, so more oxygen diffuses out of it
The upper surface is thicker, so no gases can diffuse through it
38 exam-style questions on AQA GCSE Biology 2.3 Plant tissues, organs and systems, covering 2.3.1 Plant tissues and 2.3.2 Plant organ system. Each one has a worked solution and a mark scheme showing where the marks go.