Ticks suck blood from a host organism. this is an example of
a) commensalism.
b) competition.
c) mutualism.
d) parasitism.

D) parasitism.

Explanation:

A symbiotic association can be define as the ecological association of the organisms of two different species. These organisms live in close association. The members may receive benefit, harm and may not be affected.

Parasitism is a symbiotic relationship in this the members of the two species lives in close association. In this one organism receives the benefit and the other one is harmed. The organism which cause harm is called as a parasite and the one which is harmed is a host. A parasite lives over the host body but does not kill it.

Ticks are the parasitic organisms they feed the blood over the host body. They do not kill the host organism, but causes harm by sucking blood making the host organism weak. This association of ticks and host organism is an example of parasitism.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

the answer is c on e2020, bud.