Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
I filled in each labeled square for you and wrote each percentage to the right of each square with the genotype of the last two.
Answer:
It’s C, chemical energy
If all the droplets were the same size, the droplet with the smallest charge <span>would fall most slowly through the apparatus. Basically, buoyancy is the same for all droplets but the electrical force would be different for each. The higher the electrical force the greater is the gravitational pull towards that droplet. Therefore, the droplet that has the </span>smallest charge<span> would drop most slowly.</span>