Partial preview of the text
Download Physics - Ultraviolet Radiation and more Exercises Earth science in PDF only on Docsity!
BI0421 | GENERAL BOTANY Title: Roots LECTURE #5 LECTURE # IST SEMESTER | 2022-2023 Think of some challenges a growing root tip might encounter. 1. Damage to the tip. To prevent it, it should have a_ protective layer which is the root cap. = The root cap must grow through the soil, a process aided by division’ of meristematic cells at the base of the root cap that is found adjacent to the root apical meristem. m= ‘The cap fades away for the root proper which continually pushes its way to the older root cap cells. 2. Produce a driving force to permit penetration through the soil =» Action of the apical meristem itself; continually producing files of new cells that then elongate to push the meristem further ahead. The root must anchor itself first or the plant will be pushed up and out of the soil rather than the root being § driven further into the soil. = The second role of root hairs is to anchor the roots. IMBIO4 | 1 Root cap 4 Root apical meristem is the source of regular files of cells and extend into the regions of mature root tissue. There is a mitotically inactive central region known as the quiescent center which can replace the apical meristem if it becomes damaged. The root cap layer closest to the root meristem is also meristematic. It forces files of cells that are pushed forward, while the cells on the edge grow on the side and proliferate. The maturing cells detect gravity using starch grains. For the lateral growth of roots, some cells of the pericycle divide to form a small root primordium and organize into a root apical meristem. By the time the lateral root emerges, it has formed a root cap. Its first protoxylem and protophloem had begun to differentiate; established connection to the vascular tissues of the parent root. 1. Region of cell division 2. Region of elongation 3. Region of maturation 
