When you think about the main purpose of mitochondira (to produce energy; an easy idea how to remember the function of mitochondria in our bodies is to imagine them as energy factories or power plants) it becomes easy to understand why.
Animals (including us) move a lot more compared to plants. For movement you need energy and energy needs to be produced in our bodies in order for us to be able to move. Therefore, we have mitochondria that are bigger. Not only that, animal cells usually also have more mitochondria. All of this is probably done to keep up with the increased energy demands that moving organisms have.
The answer is that they have traits that enabled them to survive in a changing environment.
During the evolution of the Earth, and later during the evolution of life, the environment was not constant. Change in the environment could lead to an extinction of some species. But, some species were able to adapt or could tolerate a wide range of environmental factors. One of the explanation, why unicellular organisms did not evolve into complex multicellular organisms is because they have traits that help them to tolerate the wide range of factors, and thus, survive in changing environment.
Answer:
1. Watch Mark Rober...He's great!
2. A shark maintains his buoyancy because a shark was the same amount of force pushing awards as gravity is pulling is downwards. So instead of sinking it floats. I know that didn't make a lot of sense but seriously, watch Mark Rober and you will know everything!!! (unlike me, a freshman)
3. P.S. If you want to learn more about buoyancy, I suggest you watch the balls in the liquid sand video
Explanation:
