-All colors of the stalk derive from two basic pigments: the red color of anthocyanin and the green of chlorophyll.
-The ratio of the concentration of these two pigments produce colors from green to purple-red to red to almost black.
- Yellow stalks indicate a relative lack of these pigments. The surface of the internode, with the exception of the growth ring, is more or less covered by wax.
b- and blade, separated by a blade joint.
-first, it enables the intake of water and nutrients from the soil;
-and second, it serves to anchor the plant.
1. the root cap,
2. the growing point,
3. the region of elongation,
4. and the region of root hairs.
1) The root cap protects the tender tissues of the growing point as the root pushes through the soil.
2) The growing point consists mainly of an apical meristem, where cell division takes place.
3) In the region of elongation, the cells increase in size and diameter until they reach their ultimate size.
4) The region of root hairs is characterized by epidermal cells forming outgrowths (hairs) which dramatically increase the root absorbing surface.