Explanation:
Cell membranes are selectively permeable. Some solutes cross the membrane freely, some cross with assistance, and others do not cross at all. A few lipophilic substances move freely across the cell membrane by passive diffusion. ... Large molecules do not cross intact cell membranes, except in certain special cases.
It allows them to study and analyze the species.
<span>The oldest known vascular plants in the northern hemisphere are Devonian
This is true</span>
Answer:
Explanation:
A keystone species is the one which plays an important role in maintaining the structure of the ecosystem. On the keystone species many other species of the ecosystem are dependent upon.
The potential effects associated with the keystone species includes the following:
1. No other species will be capable of filling the same ecological niche. Hence, the dependent organisms will suffer and the ecosystem will change drastically.
2. The ecosystem will be populated by the invasive species which will affects the population of native species.
Parasitism; the tick benefits from the human, the host.
