A. Break down sugars to use their energy directly
<span>The urinary system, also known as renal system, eliminates the majority of nitrogen-containing metabolic waste products. It
</span><span> is a group of organs which filters out excess fluid and other substances from the bloodstream. The organs that compose the urinary system are: </span> kidneys, ureters, bladder, and the urethra. The result is <span>stable balance of salts and other substances in the blood.</span>
It is thought that life arose on earth around four billion years ago. The endosymbiotic theory states that some of the organelles in today's eukaryotic cells were once prokaryotic microbes.
