biology unit 2 revision aqa gcse

E) Know that the size of stomata is controlled by guard cells, which surround them.
Water, blood, gases, glucose 1 of 25, other questions in this quiz.The alveoli are well designed by evolution to reves mecaniques the hacker perform this gas exchange efficiently.L) Know and understand that the villi in the small intestine provide a large surface area with an extensive network of thin blood capillaries to absorb the products of digestion by diffusion and active transport.The water will diffuse from a less concentrated solution to a more concentrated solution.e.Glucose) increasing in concentration (increasingly higher molarity mol/dm3).
D) Know that most soft drinks contain water, sugar and ions.
Home gcse Biology Detailed AQA gcse unit 3 Biology Quiz.




Paper 1 (Topics 1-4) and, paper 2 (Topics 5-7 starting with Y10 in Sept.Water, and the oxygen produced in photosynthesis diffuse out.Know that this requires the use of energy from respiration and this process is called active transport.HT means for higher tier students only.Since carbon dioxide is being used up in photosynthesis, the concentration gradient enables more carbon dioxide to diffuse in through the stomata.AQA gcse Science biology Unit.1.1 Dissolved substances * a) Know and understand that dissolved substances move by diffusion and by active transport.Revision Notes, study Notes, aQA gcse B3 Biology Unit.1 Movement of molecules in and out of cells.Know that the effectiveness of an exchange surface is increased by: having a large surface area, being thin, to provide a short diffusion path, (in animals) having an efficient blood supply, (in animals, for gaseous exchange) being ventilated.A large surface area to increase diffusion rate eg alveoli in lungs, villi in intestine a thin layer so diffusion times are short - cell membranes are usually quite thin, lots of thin blood vessels to bring in essential molecules for life and carry waste.Each sheet should take approximately 30 minutes to complete.
Know the movement of air into and out of the lungs is known as ventilation.