Answer:
the answer is the second option you gave
Answer:
The correct answer is keystone predator.
Explanation:
In sustaining the composition of an ecological community, a keystone species plays an essential function. In the absence of keystone species, the ecosystem would fail to exist and would become drastically different. A predator is a classic illustration of a predator, which inhibits a specific herbivorous species from eradicating the dominant species of plants. In the non-existence of predators, the herbivorous prey would increase enormously and would clean the entire essential plant species, and thus, drastically change the significance of the ecosystem.
Answer:
planetesimal is (astronomy) any of many small, solid astronomical objects, that orbit a star and form protoplanets through mutual gravitational attraction while planet is (astronomy) a body which orbits the sun directly and is massive enough to be in hydrostatic equilibrium (effectively meaning a spheroid)
Answer:
(1) they keep toxic substances out of the cell.
(2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles