3. What is the phenotype of an
individual - XHY?

the correct answer is:

a population changes in response to a change in the environment.

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

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added