The phrase "are only instructive" is correct and usable in written English.
It can be used to indicate that something serves solely to provide guidance or information without any other purpose.
Example: "The notes provided in the textbook are only instructive and do not include any personal opinions."
Alternatives: "serve only as guidance" or "are merely educational".
At this point, it is only instructive to mention that the entire query "List all growth control genes in dogs that function similar to human genes but are absent in fruit files" though feasible, is likely to be very complex if effective semantic role of the sentence can be computed.
This is not only instructive for theoretical purposes but also most relevant for the practice of disaster preparedness.
Our European Policy Workshop was not only instructive in showing the limitations of this ELSI approach, it also made us think about issues of more immediate concern for policy making in the field of SynBio and human health.
FGF instructive signal is only capable of mediating Erk/Akt phosphorylation and hairy2 induction in a SHH-mediated permissive condition.
Mr. Noriega's rise and fall is instructive only insofar as it tells us how the United States should not conduct itself when faced with a thuggish foreign dictator who happens also to have been a longtime intelligence "asset".
A glance at how high the body rides over the tires is instructive: only a few inches can signal a tired suspension that needs to be replaced ($2,100 for the best off-road job), while a truck that rides higher than normal could have had a lifted suspension for serious off-road use, which might mean a hard life.
However, comparative approaches have been instructive only in highlighting convergent similarities in catalytic chemistry with soluble serine proteases (Vinothkumar et al., 2010); other properties of intramembrane proteases remain unexplored (Erez et al., 2009; Urban, 2010).
Thus, patterns of ionic properties among non-excitable cells are endogenous instructive parameters that not only control basic behaviors of individual cells, but also serve as regulators of shape at the organ and whole organism level.
Astronomy, he tells us, is instructive not only by virtue of its exalted subject matter, but also because of its utility in the other sciences.
The contrast with Britain is instructive: the only relevant book that even begins to approach it on this side of the pond is John Kampfner's Blair's Wars, which relies on largely unattributable material with no direct access to MI6.
