Distribution and Biodiversity - Practical Skills

Question 1

How should a field be set up for random sampling?

Answer 1

By laying two tape measures at right angles on the field to set up a coordinate system

Question 2

How should students decide where the quadrats are placed?

Answer 2

By using a random-number generation to produce coordinates. Place quadrat down at the coordinates using the tape measure as a guideline

Question 3

What is the formula for estimating population size?

Answer 3

(total area/area of quadrat) * mean number of individuals counted per quadrat

Question 4

State the controlled variables of this practical

Answer 4

• Size of quadrat
• Coordinate system
• Number of quadrats per tile
• Area of sites

Question 5

Why does a random number generator need to be used?

Answer 5

To avoid bias in random sampling

Question 6

State a hazard and safety precaution involved in this practical

Answer 6

Certain plants may cause allergic reactions. Wear gloves, if affected and wash hands after practical

Question 7

When is a transect used?

Answer 7

When there is an ecological gradient in the sampling area

Question 8

Outline the procedure to sampling using a transect line

Answer 8

• Lay down a tape measure along the ecological gradient
• Place down the quadrat at the ‘0’ mark. Record the number of the required species
• Repeat the process 5m up the tape measure until the end of the transect
• Plot a graph of ‘number of individuals’ against the selected factor