Symbiosis • A close relationship between two specie that benefits at least one of the species. • Three types are: mutualism, commensalism, parasitism
Mutualism • A relationship in which both species benefit. Represented by +/+ • Examples: Saguaro Cactus and Long-eared bats. The bat benefits because the cactus flowers provide it with food and the cactus benefits because the bat carries the cactus’ pollen on its nose. Humans and bacteria in our large intestine. Bacteria helps break down food that we can’t always digest and also gives us Vitamin K and the bacteria receive food to eat.
Commensalism • A relationship in which one species benefits and the other species is neither helped nor harmed. Represented by +/0 • This is not very common because in most relationships the species are either helped or harmed at least a little bit • Example: Red-Tailed Hawks and Saguaro Cactus. The hawks have a place to build their nest, but the cactus is not harmed.
Parasitism • This relationship involves one organism living on or inside another organism and harming it. Represented by +/- • The organism that benefits is called a parasite and the organism that is harmed is called a host. • A parasite will not usually kill its host because then it loses its source of food. • Example: Ticks. They attach to a host on feed on its blood.