In this video we are going to look at the
structure of the shoot apical meristem.
Meristems are areas of undifferentiated tissue
found in the growing areas of the plant, such
as in the shoots, roots and flowers.
Meristems give rise to various plant organs
and are responsible for growth in plants.
The shoot apical meristem is found at the
top of the stem and is responsible for the
growth of the stem itself as well as the leaves
and lateral buds.
If we take a closer look at the shoot apical
meristem, we will find it consists layers
and zones.
The active shoot apical meristem has three
zones.
The central zone as the name suggests is found
in the centre of the meristem and consists
of a small number of large highly vacuolated
cells.
These cells are stem cells, some have no roles
and others undergo division to act as replenishments
for the peripheral and rib zones.
The peripheral zone flanks the central zone,
this zone has more and smaller cells than
the central zone.
Cell division in the peripheral zone gives
rise to the leaf primordia.
The rib zone is found further inside the meristem,
and under the central zone.
Cell division in this zone gives rise to the
internal tissues of the stem
The shoot apical meristem also has three layers.
Layer 1 is the outer layer.
Cell division in this layer is anticlinal,
which is where the cell walls separating daughters
cells are at right angles to the surface of
the meristem.
Layer one gives rise to the epidermis.
The next layer in is Layer 2, cell division
in this layer is also anticlinal.
Layer two gives rise to the internal tissues.
The internal layer is Layer 3.
Cell division in this layer is randomly orientated.
Layer three like layer two also gives rise
to internal tissues.
Thank you for watching.
If you found this video helpful be sure to
subscribe and hit that like button.
