Which of the following organisms is not an endoparasite?

This question is asking which of the following organisms is not an endoparasite. An endoparasite is an organism that lives and feeds inside the body of its host. Let's look at the options:

Option A: Roundworm - Roundworms are endoparasites. They live inside the body of their host and obtain nutrients from them.

Option B: Liverfluke - Liverflukes are also endoparasites. They infect the liver and bile ducts of their hosts.

Option C: Tick (Correct) - Ticks are not endoparasites. They are ectoparasites, which means they live on the surface of their host's body, usually attaching themselves to the skin and feeding on the host's blood.

Option D: Cestode - Cestodes, also known as tapeworms, are endoparasites. They live inside the intestines of their host and absorb nutrients from the digested food.

Therefore, the correct answer is Option C: Tick. Ticks are not endoparasites, unlike the other options. They are ectoparasites that live on the surface of their host's body.

It's important to understand the different types of parasites and how they interact with their hosts. Endoparasites live inside the body, while ectoparasites live on the surface. This knowledge is important in understanding how parasites can impact the health of plants and animals.

Note: This explanation assumes that the options provided are correct. If any of the options are incorrect, the answer may be different.