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why isn’t ddt an ideal pesticide? select all that apply.

it did not work well at wiping out the insect population.
over time insects started to become resistant to ddt.
ddt contaminated ground water and runoff into streams, rivers, and oceans.
ddt decomposes very slowly.
readily absorbed by animal tissue.
causes cancer in humans.

The correct answer will be option- all options except  It did not work well at wiping out the insect population are correct.

Explanation:

DDT or is the first modern synthetic insecticide used by the farmers.

Earlier it proved beneficial to the farmers but later it proved lethal to humans as it caused many hazards to the environment like:

1. caused contamination of groundwater and running water due to leaching or washing from the fields.

2. DDT proved fatal as it is non-degradable and if then slow degradation.

3. stored in animal fat tissue like in Hawks and Eagles.

4. cases of human cancer reported and increased due to the consumption of this DDT.

5. Insects like a house fly evolved resistance to DDT.

Thus, all options except It did not work well at wiping out the insect population are correct.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.