Classify these examples of symbiosis by type and explain your choice: 1) inside a human’s intestine live bacteria that make vitamin k; 2) a human picks up bacteria on his or her hands. the bacteria do not cause disease but do feed on the human’s dead skin cells; 3) a tick attaches itself to a human and feeds on the human’s blood.

The right matches are:

1. is Mutualism

2. is Commensalism

3. is Parasitism

Mutualism is an interaction between two species, in which both organizations benefit from this relationship. This is called a mutual benefit interaction. However, mutualism in the strict sense is not a binding relationship between the individuals involved.

Commensalism is a type of natural and frequent or systematic biological interaction between two living beings in which the host provides some of his own food to the commensal.

Parasitism is a biological relationship between two living beings where one of the protagonists (the parasite) takes advantage of a host organism to feed, shelter or reproduce.

a- all cells come from pre-existing cells