There is no defined limit on the capacity of the brain. The brain's capacity cannot be measured as it is not subject to a defined "space" where the memory is kept, and it is not such that each neuron is responsible for a single memory. The brain has complex mechanisms of memory storage, that even improve if trained.
Depends if they have some of the same genetic structures
Phosphate
Because it is the group of the molecules
Bc you should know i guess
Its D, im pretty sure theres not starch or acid in our DNA