In the parisitic relationship between a tick and a dog, the tick is the parasite, host and the dog is the host, parasite .

Tick is the parasite while the dog is the host

Parasitism. There are several types of biotic relationships that is occurring every single moment in the ecosystem and one is parasitism. In this scenario with human beings and mosquitos, this phenomenon of interaction is distinguished as parasitism where mosquitos draws blood that contains nutrients from the human tissue to use it as its source of food and then leaves harmful substances and bacteria in the human’s blood stream. 

What have scientists learned about plant behavior by studying the dodder plant