I choose the first question: "A farmer sprays a pesticide to control a pest insect. How might this action affect other organisms in the food web, both directly and indirectly?"
When a farmer sprays pesticide to get rid of a pest insect, it can really mess up the whole food web around that area. First of all, the pesticide doesn't just kill the pest; it can also hurt other insects that are not a problem, like bees and butterflies. These insects are super important because they help in pollinating plants, so if they get harmed, it can lead to fewer flowers and fruits.
Then there are the animals that eat those insects. For instance, if birds or other critters eat the poisoned insects, they could get sick or die too. This means that there wouldn’t be as many of those animals around because they can't find food. It's like a chain reaction where one bad thing leads to another!
Also, some of the poison can wash into nearby water when it rains, which is bad for fish and other aquatic life. The chemicals can build up in their bodies and then they might get eaten by bigger animals like frogs or even humans! So, this also affects the people because it could mean that the fish we catch might not be safe to eat.
In summary, using pesticides can harm not just the pest but a whole lot of other creatures in the food web, from beneficial insects to birds, fish, and even humans. It really shows how connected everything is in nature!