Which of the following is true?
(a) protein-coding genes make up far less of the human genome than noncoding dna.
(b) protein-coding genes and noncoding dna make up about the same amount of the human genome.
(c) protein-coding genes make up far more of the human genome than noncoding dna.
(d) noncoding dna has not been found in humans.

(A) Protein-coding genes make up far less of the human genome than noncoding DNA.

Explanation:

The human genome contains both protein-coding and non-coding sequences. However, the non-coding sequences make most of the human genome as they account for as much as 98.5% of the total human genome. The non-coding part of the human genome serves other important functions such as promoter, enhancers, silencers for gene expression.  

An only small part of the human genome serves as protein-coding genes and make exons.  

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