00:02
Hello students, in the first part of the question, a biologist wants to test a pesticide to see at what concentration it is most effective.
00:14
He has copied an experimental design that showed that adding 10 gm per litre to the watering system was effective.
00:22
He wants to test concentrations at 1, 10, 100 and 1000 gm per litre.
00:29
We need to tell what should be the positive control and what should be the negative control.
00:34
In an experiment, positive control sample will show an expected result, helping the scientist understand that experiment was performed properly.
01:16
On the other hand, negative controls are particular samples included in the experiment which are treated the same as all the others but are not expected to change from any variable in the experiment.
02:07
In this question, 1 gm per litre concentration should be taken as the negative control as it would not change from any variable and would not be effective.
02:49
On the other hand, 10 gm per litre concentration should be taken as positive control as it would cause an effect in the experiment...
