Experiment equipment etc

Question 1

Secchi disk

Answer 1

Estimating the turbidity of water

Question 2

Surber sampler

Answer 2

Sample freshwater invertebrates

Question 3

Light trap

Answer 3

Sampling night-flying moths

Question 4

Sweep net

Answer 4

Sample insects in ground vegetation

Question 5

Beating tray

Answer 5

Collecting insects in overhead vegetation

Question 6

Tullgren Funnel

Answer 6

Separate soil animals from soil/leaf litter

Question 7

Other than size, suggest one feature of a quadrant that would make finding the percentage cover of the vegetation present in zone 1 and zone 2 easier. (2 marks)

Answer 7

• Grid
• smaller areas allow totalling of each square

Question 8

Justify the use of a transect and the use of random sampling described in the method above (2 marks)

Answer 8

Transect- environmental gradient present

Random Sampling- improves accuracy of results by removing opportunity for human bias

Question 9

Describe how the standard deviation can be used to indicate if there is a significant
difference in the mean number of lobsters caught in two different years.

Answer 9

no overlap indicates the values are significantly different

Question 10

T-test

Answer 10

• Used to determine if there is a statistically significant difference between the means of data sets
• Decent sized sample (probs 10+)
• P<0.05 to be significant

Question 11

Mann Whitney U test

Answer 11

• Compares the medians between data sets
• can be used for small data sets
• one must be under and one over to be significant

Question 12

Chi-squared

Answer 12

Compares observed and expected results using the number of individual organisms