求助GWD-TN-17 Q7-Q9阅读的逻辑链

chang9049

GWD 26-Q7 to Q9

There is no consensus among researchers regarding whatqualifies a substance as a pheromone. While most agree on a basic definition ofpheromones as chemicals released by one individual of a species which, whendetected by another individual of the same species, elicit a specificbehavioral or physiological response, some researchers also specify (10) thatthe response to pheromones must be unconscious. In addition, the distinctionbetween pheromones and odorants— chemicals that are consciously detected asodors---can be blurry, and some researchers classify pheromones as a type of odorant. Evidence that pheromone responses may not involve conscious odorperception comes from the finding that in many species, pheromones areprocessed by the vomeronasal (or accessory olfactory) system, which uses aspecial structure in the nose, the vomeronasal organ (VNO), to receive chemicalsignals. The neural connections between the VNO and the brain are separate fromthose of the main olfactory system, whose processing of odorants triggerssensations of smell. But while the VNO does process many animal pheromonesignals, not all animal pheromones work through the VNO. Conversely, not allchemical signals transmitted via the VNO quality as pheromones. For example,garter snakes detect a chemical signal from earthworms—one of their favoritefoods—via the VNO, and they use this signal to track their prey.

题目我就不po了，主要想请教一下这篇文章的逻辑链。
主要是下划线那里不是很明白~~
希望看到的可以帮助一下~~，谢谢！！

mygg_1314

P和O区别不大，所以一些人认为P是一种O,但是有证据证明P中不包含O.

我是这么理解的

以及，这篇阅读的Q9答案是什么呀~以及求解释！