1. The right answer is It helps keep the organelles in place and directs their movement as needed.
The cytoskeleton provides a certain rigidity to the cell and serves for the fixation of organelles (equivalents for the organ cell for an organism).
The cytoskeleton is constantly reorganized and thus governs the internal movements (displacement of chromosomes for example) and the deformations of its membrane (production of protuberances, invaginations, sites of adhesions ...).
2. The right answer is The cell's energy level will diminish as the enzyme decreases.
Cellular respiration is the set of biochemical reactions leading to the formation of ATP, energy source of the cell.
This mechanism consumes oxygen and creates carbon dioxide as waste. That's why we talk about cellular respiration.
It is the three-step set, glycolysis, the Krebs cycle and the electron transport chain related to oxidative phosphorylation, which lead to the formation of ATP. If these reactions are not assured by lack of enzymes then there will be no production of ATP (energy production).
3. The right answer is Whales are able to conserve oxygen better than humans.
As the duration of the dive of some whale species can reach more than one hour, they use other means to breathe. In vertebrates, myoglobin, a protein, transports and stores oxygen in muscle tissue. It works like hemoglobin that carries oxygen in red blood cells. It is also myoglobin concentration very strong that makes their flesh bright red color, almost black. Thus, whales use the oxygen stored in the muscles to dive for long periods.
