A DNA molecule produced by combining DNA from different sources is known as (ONLY ANSWER IF YOU KNOW ITS RIGHT)

a mutant.

a hybrid.

a polyploid.

recombinant DNA.

A DNA molecule produced by combining DNA from different sources is known as recombinant DNA.

Explanation:

Recombinant DNA (rDNA) can be obtained by coupling DNA fragments from different sources, a process that is performed at the restriction site level and uses enzymes.  

Once rDNA has been designed —cutting out fragments of DNA that are then reassembled— it must be brought to a specific location in the cells, to be copied and expressed, using means of transport called vectors.

DNA recombination is performed in biotechnology laboratories specialized in the manipulation of genetic material.

The other options are not correct because:

this protocol describes a detailed procedure for intracellular flow cytometry staining.

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