Why do we have two types of cell division

We need two types of cells divisions for different purposes. Mitosis helps in repairing and replacing old, damaged, dead cells. Meiosis is needed for the continuation of race and also for maintenance of same number of chromosomes from one generation to the other.

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.

Aplant cell has vacuoles and a cell wall