Answer:
elliptical, spiral and irregular and elliptical are the oldest
Explanation:
Answer:
The xylem is located in the root, stem and the leaves of a plant.
The xylem contains dead cells arranged end-to-end forming continuous vessels. They have a hollow central space (lumen) through which water passes. They walls contain lignin.
The xylem carries water and minerals, up from the roots to the rest of the plant.
Answer:
Explanation:
A completely different protein
The permeability of the postsynaptic neuron changes; consequently, its membrane potential is changed as well
