What are genes?

a, the basic unit of inheritance
b, a measurable factor
c, the expressed trait
d, the observable characteristic

not sure if this is what you'r looking for eubacteria and archaebacteria

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

im not intirely sure but i think the anwser is d relative humidity