Multicellular organisms begin as a single cell. These cells then grow and undergo differentiation, the process by which cells develop specialized forms and functions.In multicellular organisms, cells are often organized into tissues, organs, and organ systems.
I would think that an unweathered rock would be jagged while a weathered rock would be smooth because of water/wind or what ever weathered it.
The auricle(pinna) collects sound waves and directs them to the auditory canal.
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