Answer:
Semi-permeable membrane
Explanation:
In semi-permeable membranes, only some substances can pass through. Sometimes, some can also pass through the channel protein molecules or transport proteins on the cell membrane.
It is called THERAPEUTIC INDEX. Therapeutic index is the comparison of the amount of a particular drug that causes the desired therapeutic effects and the amount that causes toxicity. The index can be low or high. A drug with a low therapeutic index will require only a small increase in dose to produce toxic effects in users.
Answer and Explanation:
Many elements can be responsible for this, among them, we can mention the presence and absence of predators in the different places on the rocky coast. This is because predators can influence not only the number of organisms found, but also the types of organisms.
Another element that may be the cause of this variability is the availability of resources necessary for the life of these organisms, in addition, the impact of the waves on the rocks, can cause the variability of the organisms, since some may not be able to resist the impact of the waves.
It is in between our joints to hold bones together along with muscle