e. Write a few sentences in which you address the following: Under what circumstances would underground storage organs be adaptive to the plant? A successful answer here almost certainly would define and apply the concept of "perennation" or "perennating organ."

Perennation brings adaptive advantages to the plant under unfavorable seasonal conditions

Explanation:

Perennation can be defined as the potential of plants for surviving in unfavorable seasonal periods including, for example, drought or extreme seasonal temperatures. Perennation is a process associated to the evolution of adapted 'perennating organs' capable of storing nutrients, which will be subsequently used during unfavorable conditions. Examples of such perennating organs include bulbs, rhizomes, and tubers, which are usually related to the asexual reproduction processes of plants.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation: