PLEASE HELP Describe the ten percent rule, and explain what percentage of energy a dolphin would have after it ate a fish, that ate an insect, that ate some grass.

The ten percent rule, also known as the law of ecological tithe, has to do with the effective transfer of energy that occurs at different trophic levels, corresponding to the use of one tenth of the energy from the immediate previous level.

Explanation:

The 10 percent rule was established by the english naturalist Charles Sutherland Elton, indicating that the transfer of energy from one trophic level to another is only 10 percent. This means that the level immediately above can only use one tenth of the energy produced by the level before it.

What percentage of energy a dolphin would have after it ate a fish, that ate an insect, that ate some grass?

For example, if we say that grass produces 10000 Kcal, the insect that consumes it (primary consumer) will be able to use 1000 Kcal, the fish that consumes insects 100 Kcal and the dolphin that consumes the fish only 100 Kcal.

Grass      →     Insect     →    Fish      →     Dolphin

10000            1000             100                   10

In the end the dolphin, a tertiary consumer, will only be able to produce 10 Kcal, when in the food web the producer had 10,000 Kcal.

The 10 percent rule is not entirely accurate, since the effective transfer can be less or more than 10 percent. However, in most cases, the average energy transfer is around 10%, which complies with the rule.

Heatamount of salt . . .

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.