AQA GCSE Biology paper 1 Exam Questions and Answers 100% Correct

AQA GCSE Biology paper 1 Exam Questions and Answers 100% Correct Magnification equation - Answer️️ -Magnification= image size/actual object size Light microscope- how many um in 1 mm - Answer️️ -1000 um light microscope- how many nm in 1 um - Answer️️ -1000 nm Light microscope- why can we see the nucleus and cell wall but not the mitochondria - Answer️️ -Too small and not stained light microscope- how can we see smaller parts of cells - Answer️️ -An electron microscope has much more resolution and magnification What is osmosis? - Answer️️ -The movement of water from an area with high concentration of water to an area of low concentration of water What's a solute - Answer️️ -Something that dissolves in water Investigating osmosis- what are the results - Answer️️ -High concentration of sugar in solution- water moves out of potato cells into the o gets smaller, low concentration potato gets bigger Control variables of investigating osmosis - Answer️️ -Amount of solution Investigating osmosis- why should you remove excess water with paper towels before weighing - Answer️️ -to ensure that any change in the mass of the potato is due to a change in the water content inside the potato cells How do you test for starch - Answer️️ -Add iodine to substance. Turns black if starch present How to test for protein - Answer️️ -Add biuret. Turns purple How to test for reducing sugar - Answer️️ -Add benedicts and heat for 2 mins. Turns red How to test for lipid - Answer️️ -Add ethanol then add water. Turns cloudy Investigating amylase enzyme- why do you need a water bath - Answer️️ -To maintain the correct temperature, because temperature affects reaction rate Investigating amylase enzyme- if you text at ph 3,4,5,6,7,8,9&10 why don't we know the exact optimum ph - Answer️️ -Because all though two answers may both show quick reactions, the actual optimum could be between those numbers so you need to test different phs to find exact optimum Investigating amylase enzyme- sources of error and weaknesses - Answer️️ - Measuring, starting and stopping timers Light and photosynthesis results - Answer️️ -The closer the lamp, the quicker the bubbles are produced, so higher rate of photosynthesis Light and photosynthesis- why might results be inaccurate - Answer️️ -Difficult to count very small bubbles each bubbles count as 1 no matter how big it is Light and photosynthesis- why should you leave the plant for a few minutes before starting to count bubbles - Answer️️ -It takes time for the plant to adjust to the light/temperature and for photosynthesis to reach the correct rate Light and photosynthesis- heat from the lamp is a source of error, how could you avoid this - Answer️️ -Place a glass screen in front of beaker do the light gets through but the heat doesn't Light and photosynthesis- what are the other limiting factors apart from light? Why will rate of photosynthesis level off, even with maximum light - Answer️️ -The plant also needs enough temperature and co2 Investigating reaction time- why do you have to repeat - Answer️️ -So you can calculate the mean, range of results, resolution of measurement