<span>The answer to the question is rhizome. A rhizome is an altered underground stem of a plant that is normally discovered underground, frequently conveying roots and shoots from its hubs. Rhizomes are additionally called crawling rootstalk and rootstocks.</span>
A tissue.
Then a group of tissues that work together is an organ.
The a group of organs is an organ system.
A group of organ systems is and organism.
Structure A is the mitochondria