Paper 3 biology aqa paper 2023

3 marks - answer-Stretch mediated sodium ion channels, Sodium channels open, Sodium ions diffuse in All or nothing principle 2 marks - answer-Action potential only generated when threshold is reached , High pressure is above stimulus, Time period between 0.6 and 4.0 1 mark - answer-Refractory period Two variable to control in respiration yeast experiment 1 mark - answer-Mass of glucose, Mass of yeast Yeast rate of co2 production 2 marks - answer-2.5 x10-2 Why was yeast slower in maltose over glucose 2 marks - answer-Maltose is dissaccharide, Hydrolysed into glucose Method of respiration less accurate because? This could be improved by- 2 marks - answer-Less accurate - colour is subjective Improved by - have a colour standard of the yellow as a reference for the end point Link reaction , A B C D 2 marks - answer-A-Pyruvate B-NADH C-Coenzyme A D-acetylcoenzyme A Prokaryote tick box 1 mark - answer-Second Box Mean no of bacteria in culture - answer-9.144x 10 to power of 8 Log question to bacteria one 1 mark - answer-30 generation