Kevin is studying predator-prey interactions. one day he notices a spider eating a cricket caught in its web. later that day, a bird eats the spider. how many populations are involved in his study?

3.

Explanation:

A population refers to the total number of organisms of the same species, that inhabit a distinct area at the same time, and have the capacity of interbreeding. In Kevin´s study, we have three different populations involved: spiders, crickets, and birds. Kevin is probably developing a study on population biology, focusing on the group dynamics between populations.

on december 1, 1774, the continental association was created to boycott all contact with british goods. by reversing the economic sanctions placed on the colonists, the delegates hoped britain would repeal its intolerable acts.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.