Paper 2 RPAs

Question 1

RPA 7: Reaction Time

Answer 1

Person 1 sits on stool with good upright posture
Person 1 places the forearm of their dominant hand across the table with their hand overhanging the edge
Person 2 holds ruler vertically with 0cm mark between thumb and forefinger
Person 2 tells person 1 to prepare to catch
Person 2 drops ruler randomly
Person 2 has to catch ruler
Person 2 recorded measurement at the top of Person 1s thumb
Mean time
Conversion table
Switch places

We could practice or use weak hand or see the effect of caffeine

Question 2

RPA 8: Plant reponses

Answer 2

Place cotton wool in three Petri dishes and soak them with equal volumes of water. Place ten mustard seeds in each dish. Leave dishes in warm place. Water seeds each day with same volume of water. After a few days the seeds will germinate, check number of seedlings are the same. Hold stems and measure height of each seedling. Place one dish in full sunlight, one in partial sunlight and another in complete darkness. Measure height of each seedling for five consecutive days. Measure mean.

Question 3

RPA 9: Sampling Organisms

Answer 3

Place two tape measures at right angles. Random number generator. Place a quadrat at the coordinate, record number of daisies. 10 samples. Estimate total daisies.
Factor - transect - quadrants one meter apart across 10 metres and measure light intensity

Question 4

RPA 10: Decay

Answer 4

Place 5cm3 of lipase in a test tube and label it.
In a separate test tube add 5 cm3 of milk and 7cm3 of sodium carbonate with some creol red. It should be purple. Place a thermometer in mil test tube. Place test tubes in beaker at temp chosen. Wait until test tubes reach temp of beaker. Transfer 1cm3 of lipase to the milk. Start a timer. Indicator will change to yellow and stop timing. Repeat at different temperatures.
Calculate a mena. Use a clean milk test tube each time.