When a mosquito bites you, you are the HOST and the mosquito is the PARASITE.
Variations are beneficial for the survival of the species. Populations of organisms fill well-defined places, or niches, in the ecosystem, using their ability to reproduce.However, if some variations were to be present in a few individuals in these populations, there would be some chance for them to survive.
The alveoli. These little air sacs are found on the end of the bronchioles and are the place where oxygen enters the blood and the carbon dioxide leaves.
