One reason that regulation of gene expression is important is that it saves energy and materials from being used when they are not needed. although most genes have more than one form of regulation acting upon them, at which point would regulation be most efficient in conserving energy and materials if the product of a gene is not needed?

Transcriptional Regulation  

Explanation:

Eukaryotic gene expression can be regulated during the time of transcription and RNA processing, which takes place in the nucleus of the cell and then during the time of protein translation in the cytoplasm.

Further regulation is being carried during the time of post transnational modification. The conservation of energy is very important because it saves the overall energy and space in the body.

Hence, the most important point for the regulation would be transcriptional regulation.

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

golgi body just took the test on edge