Which structure in plants produce a substance that protects the extending roots from developing friction?

The right answer is the root cap.

In botany, the root cap represents the end of a root that serves both to protect the apical meristem of the root, to facilitate its penetration into the soil through mucigel and to control the reaction of the root to gravity through the columella containing statocytes. The perception of gravitropism is thus located in the headdress of the root.

This root apex may be lacking in certain plants such as submerged plants (ceratophylum) or horse chestnut.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).

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."