Cells - tissues-organs-organs system-organisms
(1) normally harmless cat antigens stimulated
<span>the immune system</span>
Vascular tissue<span> is a complex conducting </span>tissue<span>, formed of more than one cell type, found in </span>vascular<span> plants. The primary components of </span>vascular tissue<span> are the xylem and phloem. These two </span>tissues<span> transport fluid and nutrients internally.</span>
