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.
Answer:
Lichens are not parasitic when they grow on trees, they just use the tree bark as a home. They enrich the soil by trapping water, dust and silt. When lichens die they contribute organic matter to the soil, improving the soil so that other plants can grow there.
Loss of habitat from any number of causes is the main reason for species endangerment currently.
Organism in an eniornment can compte for food
You'll want to double check, but I think it's (a) cotyledon.
