SPECIFIED PRACTICALS

Question 1

Investigation into factors affecting the abundance and distribution of a species

Answer 1

1. Lay 20m tape measures at right angles along two edges of the area to survey
2. Roll two 20 sided dice to determine the co-ordinates
3. Place 1m2 quadrant at the place where the coordinates meet
4. Count the number of (any plant) with the quadrat. Record this result
5. Repeat steps 2-4 for at least 25 quadrants

Question 2

Investigation into variation in organisms

Answer 2

1. Arrange the photographs of the woodland snails face down and randomly select 50
2. Categorise the snails selected into one of the 4 different variants and count the number of each.
3. Repeat steps 1- 2 for the grassland snails

Question 3

Investigation into factors affecting reaction time

Answer 3

1. Ask your first volunteer to sit in the chair with good upright posture and eyes looking across the room.
2. Have the volunteer place their forearm so it extends over the edge of the table.
3. Ask the volunteer to place their thumb and index finger on either side of the bottom of the vertically placed ruler. The number “1” should be on the bottom, the “30” near the top.
4. Now, ask your volunteer to remove their fingers from the ruler while you continue to hold it so that the bottom of the ruler is at a height of 2 cm above the fingers.
5. Tell your volunteer that you will release the ruler without warning. Their job will be to catch it with their thumb and forefinger as soon as they sense it dropping.
6. Drop the ruler. When your volunteer catches it, record the number on the ruler displayed just over the thumb. The lower the number, the faster the reaction time.
7. Conduct five trials with the same volunteer, dropping the ruler from 2cm above their fingers each time.
8. Repeat the experiment with at least five other volunteers and record your results in a suitable table