Endoplasmic reticulum is the answer.
If you were to cross a large redwood tree, like for an example a sequoia, from the middle of the trunk you would first cross the annual rings, indicators of the trunk growth over the years, then after that you would cross the phloem, the ''piping'' of the tree responsible for the transport of water throughout the tree and in the end you would cross the tree's bark, the protective layer on surface of the trunk.
Answer:
Active Transport
Explanation:
Active transport is the process of transport of substances from region of their lower to that of higher concentration. Since the transport occurs against the concentration gradient, it is energy requiring process and needs input of energy to occur.
In given example, liver cells transports vitamins against the concentration gradient in energy dependent manner. Therefore, it is an example of "active transport".
