This experiment is an example of hypothesis-based science. What question did the researchers ask? What question did the researchers ask? Do male guppies in pools with pike-cichlid fish have brighter color patterns than females in the pool? Do female guppies prefer to mate with males with bright color patterns or drab colors? Can predation result in selection for color patterns in guppies? Do killifish prefer to prey on juvenile guppies or adult guppies?

Can predation result in selection for color patterns in guppies?

Explanation:

Researchers took guppies from their pools that is seen to have pike­cichlid fish (a huge guppy predators) and then implanted it in another pools that is seen to have the killifish (they are not really active predators that prey wholly on the childish and immature guppies). They then estimated to see if the color patterns in the grafted or transferred population undergo some alterations in the course of time.

"d.) carbon dioxide and hydrogen sulfide"