C.
explanation- in the case of pure water there are always going to be the same number of hydrogen ions and hydroxide ions present.
Answer: Fossils are rare because most remains are consumed or destroyed soon after death. Even if bones are buried, they then must remain buried and be replaced with minerals. If an animal is frozen like the baby mammoth mentioned above, again the animal must remain undisturbed for many years before found.
Explanation:
To release the energy stored in carbon-containing molecules, such as sugars, autotrophs and heterotrophs break these molecules down in a process called cellular respiration. In this process, the carbons of the molecule are released as carbon dioxide.
Well, the cell membrane is full of a bunch of little holes. Sort of like a coffee filter.
What does a coffee filter do? Well, you put the coffee in it and run water through it. Then what?
The water is small enough to pass through the filter and bring some of the coffee with it. But the coffee grains are too big to pass through the filter. If we really wanted the coffee grains to get through the filter, we could force them through. Do you want chunks in your coffee? Eww.
Now the cell membrane is the same way, the little things (water, carbon dioxide, oxygen, sugar) are all small enough to fit through the tiny holes in the cell membrane. This is called, "Passive Transport". Because the things can passively float their way in and out of the cell.
Now some other things are too big to fit through, so to make them fit, the cell has to use energy to open itself a little bit more to let them in. This is called, "Active Transport". Because the cell needs to be active and use energy to let those things in.
<span>Now Osmosis is the transfer of water and salts (basically) throughout the cell.
Both Salt and Water are small enough to fit through the Cell Membrane using "Passive Transport".
I've posted this same response earlier, and it is my writing.</span>
Answer: a rock doesn’t have a mitochondria.