B6.1.2

Question 1

What are the steps for the capture recapture technique

Answer 1

1. Capture organisms from a sample area
2. Mark organisms then release back into the environment
3. At a later date recapture organisms in the original sample area
4. Record number of marked and unmarked individuals

Question 2

Formula for estimated population size

Answer 2

Estimated pop size = first sample size x second sample size/ number of recaptured marked individuals

Question 3

How can you sample plants

Answer 3

Using a quadrat

Question 4

What is a quadrat

Answer 4

A quadrat is a frame divided into grids. You place it on the ground and record the type and number of organisms within each sector.

Question 5

What do you do with the data

Answer 5

You work out the mean and multiply it by the total area size to get total population

Question 6

How can you make this random sampling

Answer 6

You can make it random sampling by marking out a grid on the sample area. Then using a random number generator to choose the coordinates to place it in a quadrat.

Question 7

What is non-random sampling used for

Answer 7

When using transects it’s to show how the distribution of organisms change over a distance.