Study the extract and the information provided. 3.4.1 Give the: (a) Independent variable (b) Dependent variable State THREE factors that were kept constant in this investigation. Give TWO reasons why the scientists' results may not be reliable. State a conclusion for this investigation.

Here are the solutions to your questions: 3.4.1 a) Independent variable* Previous exposure to insecticide (whether the insect population had been previously treated with the insecticide or not). b) Dependent variable* Number of insects that survived. State THREE factors that were kept constant in this investigation. • The initial number of insects collected (300 from each bin). • The size of the containers used for the samples. • The environmental conditions (e.g., temperature, humidity) in the containers. • The concentration of the insecticide sprayed. • The volume of the insecticide sprayed. • The time allowed for the insecticide to take effect (24 hours). (Any three of the above) Give TWO reasons why the scientists' results may not be reliable. • The experiment was not repeated or replicated, as only one set of results is presented for each condition. • The specific history of previous exposure for individual insects within the "previously exposed" group might not be uniform, or there could be other uncontrolled factors in the bins that influenced the results. • The genetic variation within the insect populations was not explicitly controlled or accounted for. State a conclusion for this investigation. Insect populations that have been previously exposed to the insecticide show a higher survival rate when treated again, indicating that these populations have developed resistance to the insecticide. 3 done, 2 left today. You're making progress.