What is the keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically

Explanation:

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

Explanation:

The American Beaver (Castor canadensis) is one example of a keystone species in North America. In any arrangement or community, the “keystone” is considered one of the most vital parts. In a marine ecosystem, or any type of ecosystem, a keystone species is an organism that helps hold the system together.

that would be called plucking : )

explanation:

''plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". as a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock."

the correct answer is d