Paper 3 biology paper 2024 questions and answers, Exams of Biology

Download Paper 3 biology paper 2024 questions and answers and more Exams Biology in PDF only on Docsity! Paper 3 biology paper 2024 questions and answers Describe how pacing corpuscle produces generator potential 3 marks - Correct Answers Stretch mediated sodium ion channels, Sodium channels open, Sodium ions diffuse in All or nothing principle 2 marks - Correct Answers Action potential only generated when threshold is reached, High pressure is above stimulus, Time period between 0.6 and 4.0 1 mark - Correct Answers refractory period Two variable to control in respiration yeast experiment 1 mark - Correct Answers Mass of glucose, Mass of yeast Yeast rate of co2 production 2 marks - Correct Answers 2.5 x10-2 Why was yeast slower in maltose over glucose? 2 marks - Correct Answers maltose is disaccharide, Hydrolyzed into glucose Method of respiration less accurate because? This could be improved by- 2 marks - Correct Answers 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 - Correct Answers A-Pyruvate B-NADH C-Coenzyme A D-acetyl coenzyme A Prokaryote tick box 1 mark - Correct Answers second Box Mean no of bacteria in culture - Correct Answers 9.144x 10 to power of 8 Log question to bacteria one 1 mark - Correct Answers 30 generation Two reasons why bacteria could grow in culture containing chloramphenicol 2 marks - Correct Answers Concentration was too low to kill all, Mutation How is SCFR destroyed by lysosome? 2 marks - Correct Answers Vesicle binds with a lysosome, Lysosomes digest SCFR Diversity of fish formula year’s value 1 marks - Correct Answers 1982 and 2003 Describe and explain 1997 results 2 marks - Correct Answers 1997 had highest no of species, However few species were present in very large numbers Why journalist conclusion on power station might not be valid 4 marks - Correct Answers species richness lower after 29 years, Data only for one fish community, Other communities may have different fish species, Volume of heated water may have varied Two types of cell that can stimulate immune response 2 marks - Correct Answers Pathogens, Abnormal body cells Why olive oil applied to left ear of the mice 1 mark - Correct Answers as control experiment to show its OXA affecting immune response