Question

parasitism
deaths>births
a symbiotic relationship where one organism benefits and one is harmed
a group of the same type of organisms living in an ecosystem
a population that is eaten by organisms from another population

Explanation:

Parasitism is a symbiotic relationship in biology where one organism (the parasite) benefits and the other (the host) is harmed. The other descriptions refer to population - decline (deaths>births), a population (a group of the same type of organisms living in an ecosystem), and predation (a population that is eaten by organisms from another population).

Answer:

a symbiotic relationship where one organism benefits and one is harmed