Which plant part preforms a function similar to that of the human skeleton?

Lignified heartwood, in the plants that have that, provides a support function.

Explanation:

Heartwood doesn't provide the "reserve of calcium" that a human skeleton does, nor does heartwood function in muscle attachment and movement via muscle.

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).

condensation. good luck!