Selective permeability, made possible in cells by the phospholipid bilayer that makes up the plasma membrane, is basically monitoring and regulating what can and can't enter the cell. It is carried out by a series of membrane proteins that act as channels to polar molecules, opening to allow them in and closing to prevent their entry. This is possible because the hydrophobic tails of the phospholipid molecules repel polar molecules and so prevent their entry unless through a channel.
The answer to the question is that it is True
Answer:
Explanation:
In a cross-section of an adult tree trunk, the outer layer that interacts with the environment is called periderm (Layer D). The second layer that follows the periderm is the phloem (Layer C). The next layer is the cambium, which produces phloem cells and xylem cells (Layer B). The secondary xylem follows the vascular cambium (Layer A) and finally, the medulla is located in the middle of the trunk.
The secondary xylem proceeds from the vascular cambium activity. Its cells are orientated in different ways composing the vertical/axial system and the horizontal/transversal system. The secondary xylem is essential to the tree growth in high because of its resistance and the capacity to transport water long distances. Secondary xylem functions are to transport water and minerals through its vessels and tracheids, to provide support and resistance to the plant, and to store reserve substances.
What is the question you are asking
The word that would fit the blank is vascular. You are consuming the vascular tissues of a plant when consuming a celery stick. This part of the celery is called the petiole. This is the stalk that joins a leaf and a stem. This part is made up largely of vascular tissues.
