4.2 explain how quadrats can be used to estimate the population size of an organism in two different areas

4.2 •you can estimate the population size

                 •place a 1m2 quadrat randomly on the ground 

                 •count all the organisms

                 •multiply the number of organisms by the total area (m2) of the habitat

                           •you can do this in another area to compare population sizes

       •the sample point may not be representative of the whole area

       •sample size effects accuracy of the estimate

                 •it is better to use the quadrant at several points to get an average in 1m2, then multiply by the total area