A relationship between two species where one benefits while the other is harmed.

A relationship between two species where one is harmed by the other, but the other is unaffected.

A tapeworm and a cat have this type of relationship.

Cattle egrets forage (feed) in fields among cattle. The egret gets easy access to flying insects stirred up by the cattle, and the cattle don't care if they are there or not. This is an example of:

Remora are small fish with a sucker-like organ that allows them to attach themselves to larger animals like a shark. By doing this, the remora is able to gain protection from the presence of the shark while also traveling long distances more quickly. The remora is light enough to be carried with little effort, and the remora does no damage to shark. This relationship demonstrates which of the following?

Ostriches and gazelles feed next to each other. They both watch for predators and alert each other to danger. Since the visual abilities of the two species are different, they can each identify threats the other animal would not as readily see. This is an example of:

Epiphytes are a class of plants that grow in the crooks of tree branches. They simply use the tree branches as a way to be higher - closer to the sunlight needed for photosynthesis. The trees aren't affected by this relationship. This is an example of which type of symbiosis?

Some weeds are known to secrete alelopathic substances that can inhibit the growth of other plants. The weeds could grow regardless of whether or not they secreted these poisonous substances, but they hinder the growth of other plants by doing so. This is an example of: