1. Investigation 1- IB2 Random sampling and Quadrats (G.1.3)

2. Population A group of organisms of the same species living in the same area at the same time

3. Measuring Populations It is usually impossible to count every member of a population Ecologists often use methods to estimate the population size

4. Random Sampling A sample, or part of an area, is chosen to illustrate what the whole population is like In a random sample, every individual has an equal chance of being selected Small numbers of individuals, in randomly located parts of the total area, are counted This method is suitable for organisms that do not move around!

5. Random Sampling – Quadrats Square sample areas of equal size, marked out by a frame Useful when study area is uniform When study area is sloped or irregularly shaped, quadrat can be used together with a line transect (which we did in grade 10)

7. Our study is in the quad… analyzing red clover and dandelion population sizes..

8. Random sample generating using your TI-83 Stat Edit L1 Highlighted Green / + sign MATH PRB 5- Random Integer (1,5,10) L1 (1, 10, 10) L2 Green + Enter * Do the same for L2 to get your co-ordinates.

9. Calculating population Population size= mean number per quadrat * total area / area of each quadrat Page 152 leaf book

10. After the population size has been determined of each you can conclude whether you or not you think pesticides are used or not on the school grounds… How can we be sure?