1. No conversions. The greatest advantage of SI is that it has only one<span> unit for each quantity ( a type of measurement). This means that it is never necessary to convert from one unit to another (within the system) and there are no conversion factors for students to memorize.
2. </span><span>No fractions. SI uses decimals exclusively, eliminating clumsy fractions and mixed numbers.</span>
The herbaceous stem is composed of vascular bundles (xylem and phloem) arranged in a circle around a central core of spongy tissue made up of parenchyma cells, called the pith. Surrounding the vascular bundles is a layer known as the cortex, which varies in thickness from species to species.