I belive the answer is all of the above
Microvilli which line down the luminal surface of those epithelial cells represent the resorptive function of the proximal tubule.
<span>The high quantity of mitochondria inside the epithelial cells of the proximal convoluted tubule is needed in order to supply the energy for the active transport of sodium ions (to enter the cell from the luminal side).</span>
My Answer: Vestigial organs
Why?: " Vestigial organs are physical structures that were fully developed
and functional in an ancestral group of organisms but are reduced
and unused in the later species."
Hope I helped! :D
1.) A bluebarry has a greater density than a strawberry.
2.) The blueberries sunk while the strawberries float
3.) Blueberries carry a larger density than water
4.) Strawberries have less density than water
