What is the meaning of apex explain it's types
The terminal part of the shoot with the leaf primordia is the shoot apex where primary organisation of the shoot is initiated.
In size and shape it varies enormously, but in a general way it can be said that the shoot apex is more or less convex in longitudinal section.
The Root Apex:
In comparison to the stem apex the apical meristem of the root is simpler, because of the absence of nodes and internodes and lateral appendages. But it has a protective cap, which acts as the buffer between the root-tip and the soil particles.
As cap occupies the terminal position, the apical meristem is subterminal here. Curiously enough, growth in the root-tip proceeds in two directions opposite to each other—towards the tip in the cap and away from the tip in the root proper.
Similarities between Shoot Apex and Root ApexØ Both shoot apex and root apex are the growing terminal regions.
Ø Both contain apical meristem.
Ø The tissue in both shoot and root apex are primary tissue.
Difference between Shoot Apex and Root Apex Sl. No.Shoot ApexRoot Apex1 | Shoot apex is positively phototropic. | Root apex is negatively phototropic. |
2 | Shoot apex is negatively geotropic. | Root apex is positively geotropic. |
3 | Apical meristem in shoot apex is terminal in position. | Apical meristem in root apex is sub-terminal due to the presence of root-cap. |
4 | Shoot apex is protected by a crown of young leaves. | Root apex is protected by a root-cap. |
5 | Shoot apex possesses leaf primordia. | Leaf primordia are absent in root apex. |
6 | Shoot apex is dome-shaped. | Root apex is hemispherical or cup-shaped. |
7 | Quiescent centre absent in the shoot apex | Root apex is surrounded by a quiescent centre. |
8 | Cells are comparatively more differentiated in shoot apex. | Cells are comparatively less differentiated. |
9 | Shoot apex is comparatively long. | Root apex is comparatively short. |