Fertilization by more than one sperm would result in a polyploidy and an inviable zygote. What is the first line of defense against polyspermy?a. species specific recognition of proteins on the outer coat of the egg. b. changes in the membrane potential of the egg prohibiting additional sperm from entering.
c. capacitation in the sperm fertilizing the egg.
d. products released from the egg changing the zona pellucida of the egg and prohibiting additional sperm from entering.

Ithink the answer is d.

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.