Practicals

Question 1

Describe the practical to measure the population size of a species using random sampling

Answer 1

1. Use a 0.5m by 0.5m quadrat
2. Place two 20m tape measures at right angles on the ground
3. Take two bags each one with the numbers 1-20 inside. Students should work in groups of three
4. Student 1 should take a number from first the bag e.g. 9 and go and stand at the 9m mark on the vertical tape measure
5. Student 2 should take a number from the second bag e.g. 10 and go and stand at the 10m mark on the horizontal tape measure
6. Then student 3 should take the quadrat and place it at the 9m x 10m mark on the ground and count the number of organisms of the same species in the quadrat
7. Now the students should take the numbers back to the bags and repeat the process 9 more times to get a total of 10 samples
8. Now calculate the total population size using the equation :

(total area/area of quadrat) x number of organisms counted in the sample

Question 2

Describe the practical used to investigate the effect of light intensity on the distribution of a series

Answer 2

1. Place 20m transect tape measure line onto the ground from a tree to the other end of the area
2. Place a 0.5m by 0.5m quadrat at the 1m mark on the transect line beneath the tree and count the number of organisms from the same species inside the quadrat. Measure the light intensity using a light meter
3. Now move up by 1m and repeat this process until you reach the end of the transect line
4. Now repeat the entire process again 3 times by using parallel transect lines to see the trend in distribution