The cruelest thing that you could do is to hurt or punish someone who is innocent. This is sometimes called the principle of innocent victims.
To penetrate something is to go through it, to break through its surface. When you penetrate the skin with a needle, you are causing it to break open and bleed.
Sporozoites are small parasites that live in the blood of some animals. They are sometimes called blood flukes.
Merozoites are the reproductive cells of a parasite. They are small and round, and they look a lot like cells in the human body.
Convulsions are a type of seizure. They can be mild or severe, but they all involve muscle spasms.
To infect something is to cause it to get sick or to have something bad happen to it. When you infect your computer with a virus, you're causing it to get infected with a virus.
Plasmodium is a microscopic parasite that can cause malaria. It is often found in the blood of people who are infected with the disease.
To overpower someone is to take control of them or to defeat them easily. If you overpower someone, they can't resist your commands.
To adapt is to change or to become better suited for a new situation. When you adapt to a new culture, you learn the customs and slang of that culture.