brain is the organ which does play a role in mechanical or chemical digestion
Answer: Option B) Coelom
Explanation:
Hydrostatic skeleton is the type of skeleton possessed by soft-bodied animals such as earthworms and sea anemones. Fluid is secreted to fill the cavity spaces (coelom) in their body. The fluid then presses against the muscular body wall, causing the muscles to contract exerting pressure against the fluid thereby causing motion
Thus, coelom is the fluid cavity of the earthworm that gives it a hydrostatic skeleton
Biogeographic isolation refers to the separation of the members of the similar species, or a group of organisms, which breed and generate offspring that can further give rise to young ones.
The separation can be achieved by the geographical forces like oceans, rivers, and mountains, and by the biological forces, like hunting times, and spring or fall mating.
Watershed is the place where water of rain and snow get stored. The watershed contains surface water-and wetlands--and all the underlying ground water,lakes, streams, reservoirs. Lake is the major component of the watershed . The watershed can be used for various purpose like dams, hydrological modification etc.