Question

Why is it useful for an ecologist to identify the keystone species in an ecosystem? (1 point) The keystone species is only important in early stages of succession, and so the ecologist can safely ignore changes in its population at later stages. The keystone species is the most susceptible to pollution, and so its numbers give an indication of the levels of pollutants in an area. The keystone species is critical to maintaining the stability of an ecosystem, and changes in its population indicate changes in ecosystem health. The keystone species is important for the cycling of matter and must

Answer 1

2. (C)

Answer 2

its C

Answer 3

Competition over resources occurs between organisms (1 point)
participating in an herbivorous relationship.
forming a symbiotic relationship.
attempting to occupy the same niche.
initiating primary succession after a disturbance.

Answer 4

Again C

Answer 5

attempting to occupy the same niche.

Answer 6

The lowest trophic level in an ecosystem (1 point)
has the lowest quantity of stored energy.
has the greatest biomass.
is made up of heterotrophs.
contains detritovores.