Answer:
muscle cells in the legs of a marathon runner
Explanation:
Mitochondria are the powerhouse of cells and serve as a site for the aerobic stage of cellular respiration. Cellular respiration is complete oxidation of nutrients in the presence of oxygen to produce a large number of ATP molecules. Therefore, the cells that require more ATP molecules as an energy source would most likely have a greater number of mitochondria.
Muscle cells are responsible for body movement. Muscle cells in the legs of a runner would require a constant supply of ATP during running since muscle contraction requires ATP. To sustain the continuous muscle contraction during the marathon, the muscle cells in the legs of the runner would have most number of mitochondria.
A protist has a nucleus inside of it to make it a Eukaryote, if it had no nucleus it would be consider a Prokaryote
17=3
18=4
I'm not that sure about 17, but I think it's right
Spinal cord is the part of the central nervous system which is used to serve as the main communication link between the body and brain
Plants will usually droop their leaves and wilt on a hot day due the amount of water they're not receiving. This can be advantageous to a plant because this releases moisture in the air called <span>transpiration.
Hope that helps. -UF aka Nadia</span>