If an experimenter wants to use the GFP method but needs to detect the presence or absence of several proteins at the same time, he can take advantage of mutational variants of GFP that emit what light?

different colors

Explanation:

The green fluorescent protein (GFP) is a type of protein widely used in molecular biology laboratories because this protein can be used to detect the expression of proteins and to identify cellular structures. This protein displays green fluorescence when it is excited by blue light and, in the last years, many variants of the GFP protein have been developed. The altered GFP proteins react to distinct wavelengths of light, thereby emitting light to different colors. The mutants forms of the GFP protein are produced by genome engineering techniques that generate modifications capable of altering the folding of the normal GFP protein.

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d