Paper Two Required Practicals Flashcards
What is the investigation for measuring human reaction time?
❶ working with a partner, person A holds out their hand with a gap between their thumb and first finger.
❷ person B holds the ruler with the zero at the top of person A’s thumb.
❸ person B drops the ruler without telling person A and they must catch it.
❹ the number level with the top of person A’s thumb is recorded in a suitable table and repeat this five times.
❺ swap places and record another five attempts.
How do you investigate the effect of light on the growth of newly germinated seedling?
❶ put cotton wool into three petri dishes and add the same volume of water to each dish.
❷ add ten seeds to each dish and place them in a warm place.
❸ allow the seeds to germinate and add more water if the cotton wool dries out.
❹ once the seeds have germinated, ensure the petri dishes each contain the same number of seeds and remove any extra seeds if necessary.
❺ one petri dish will sit in full light on a windowsill, the second will be in a dark cupboard and the final dish will be placed in partial light.
❻ every day for one week, measure the height of each seedling and record the results in a table.
⟶ calculate the mean of the seedlings each day, and compare the mean heights in the three different locations.
How do you measure the population size of a common species in a habitat?
❶ choose a starting point on a field in an area where the grass is often cut.
❷ use random numbers to generate a set of coordinates to place your first quadrat.
❸ count the number of different plant species within this quadrat.
❹ return to your starting position and repeat steps two and three a further 14 times using different random numbers.
❺ repeat all the steps in a part of the field which the grass is infrequently cut.
⟶ compare your results by calculating a mean for each location.
