Reuqired Practicals

Question 1

Required Practical 7-Reaction Time (B5)

Answer 1

Method:
1. Rest your non-daminant arm on the table with vour hand hanging over the side
2. Get another person to hold the ruler over your hand and drop it without warning
3. Catch the ruler in the fastest time possible
4. Record the distance you caught the ruler
5. Use the conversion toble to convert the distance into seconds
6. Repeat steps 1-4 a further 9 times

Question 2

Required Practical 9 - Distribution of Organisms (B7)

Answer 2

Method
1. Mark a shaded ares (10 x 10 m) with two meosuring tapes at right angles to each other
2. Use a random number generator to pick ten coordinates for the sampling area e.g. (2,5)
3. Ploce the 1m~ quadrat in the bottom left comer of the coordinate spoce
4. Count the number of plants in the quodrat.
5. Move on to the second coardinate and repeat steps 3-4 until 10 coordinates have been sampled
6. Calculate the mean number of plants per mi for the area.
7. Estimate the mean number of plants in the oreo
8. Repeat the some process in the secand non-shoded area.

Question 3

Required Practical 10 - Decay (B7)

Answer 3

Method
1. Add 5cm’ of milk, Som’ of sodium carbonate and 5 draps of phenolphthalein to a balling tube.
2. Place the miture into a z rack at room temperature and record the temperature
3. Add 1 cm’ of lipase solution to the boiling tube and start the stop clock
4. Time how long it takes for the solution to turn from pink back to white
5. Repeat at 35°C and 45 C and 55°C using thermostatically controlled water baths
6. Ensure lipase and milk solution are not mixed before 5 minutes