Which type of variable is kept unchanged throughout the experiment so as not to influence the experiments outcome?

The variable that stays the same throughout the experiment is called the Constant Variable.

Explanation:

It remains constant, so it is called the constant variable.

this transfer is call conjunction

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.