GCSE Biology paper 1(AQA) Study
Guide Exam And Actual Answers.
Magnification equation - Answer Magnification= image size/actual object size
Light microscope- how many um in 1 mm - Answer 1000 um
light microscope- how many nm in 1 um - Answer 1000 nm
Light microscope- why can we see the nucleus and cell wall but not the mitochondria - Answer Too
small and not stained
light microscope- how can we see smaller parts of cells - Answer An electron microscope has much
more resolution and magnification
What is osmosis? - Answer The movement of water from an area with high concentration of water to
an area of low concentration of water
What's a solute - Answer Something that dissolves in water
Investigating osmosis- what are the results - Answer High concentration of sugar in solution- water
moves out of potato cells into the solution.potato gets smaller, low concentration potato gets bigger
Control variables of investigating osmosis - Answer Amount of solution
Investigating osmosis- why should you remove excess water with paper towels before weighing - Answer
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 - Answer Add iodine to substance. Turns black if starch present
, How to test for protein - Answer Add biuret. Turns purple
How to test for reducing sugar - Answer Add benedicts and heat for 2 mins. Turns red
How to test for lipid - Answer Add ethanol then add water. Turns cloudy
Investigating amylase enzyme- why do you need a water bath - Answer 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 - Answer 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 - Answer Measuring, starting and
stopping timers
Light and photosynthesis results - Answer The closer the lamp, the quicker the bubbles are produced,
so higher rate of photosynthesis
Light and photosynthesis- why might results be inaccurate - Answer 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 - Answer 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 - Answer
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 - Answer The plant also needs enough temperature
and co2
Guide Exam And Actual Answers.
Magnification equation - Answer Magnification= image size/actual object size
Light microscope- how many um in 1 mm - Answer 1000 um
light microscope- how many nm in 1 um - Answer 1000 nm
Light microscope- why can we see the nucleus and cell wall but not the mitochondria - Answer Too
small and not stained
light microscope- how can we see smaller parts of cells - Answer An electron microscope has much
more resolution and magnification
What is osmosis? - Answer The movement of water from an area with high concentration of water to
an area of low concentration of water
What's a solute - Answer Something that dissolves in water
Investigating osmosis- what are the results - Answer High concentration of sugar in solution- water
moves out of potato cells into the solution.potato gets smaller, low concentration potato gets bigger
Control variables of investigating osmosis - Answer Amount of solution
Investigating osmosis- why should you remove excess water with paper towels before weighing - Answer
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 - Answer Add iodine to substance. Turns black if starch present
, How to test for protein - Answer Add biuret. Turns purple
How to test for reducing sugar - Answer Add benedicts and heat for 2 mins. Turns red
How to test for lipid - Answer Add ethanol then add water. Turns cloudy
Investigating amylase enzyme- why do you need a water bath - Answer 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 - Answer 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 - Answer Measuring, starting and
stopping timers
Light and photosynthesis results - Answer The closer the lamp, the quicker the bubbles are produced,
so higher rate of photosynthesis
Light and photosynthesis- why might results be inaccurate - Answer 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 - Answer 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 - Answer
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 - Answer The plant also needs enough temperature
and co2
