Botany lecture notes

Apical Meristem in Shoot: Structure and Organization


shoot-apical-meristem

Shoot Apical Meristem
Apical Organization of Shoot Meristem

Apical meristem

Ø  Apical meristem is a patch of meristematic tissue present in the apex (tips) of shoot and roots in plants.  

Shoot apex:

Ø  Shoot apex is the growing tip of the stem.

Ø  It is an undifferentiated region with meristematic cells.

Ø  From this region the plant growth proceeds.

Ø  The shoot apex also produces lateral organs such as leaves, branches and flowers.

Ø  Below the apical meristem, different tissue zones are progressively differentiated.

apical-meristem

Tissue zones in the shoot apex

Ø  Three main tissue zones are present on the shoot apex of plants, they are:

$.  Protoderm: Protoderm gives rise to the epidermis of the plant.

$.   Procambium: Procambium gives rise to primary vascular tissue (xylem & phloem).

$.   Ground meristem (fundamental meristem): The ground meristem gives rise endodermis, pericycle, cortex, medulla and pith.

Continue reading

biology-ppt-free-download

Secretory Tissue in Plants PPT (Structure, Classification and Examples)


Plant Science PPT

Secretory Tissue System in Plants PPT
(Structure, Classification, Functions and Examples of Secretory Tissues in Plants)

What is Plant Secretion? What are Secretory Tissues? How Plant Secretory System is Classified? Different Types of Secretory Systems in Plants, External vs Internal Secretory System in Plants, Glandular Trichomes, Nectaries and Hydathodes in Plants, Digestive Glands of Drosera, Salt Glands of Mangrove Plants, Colletors, Floral vs Extra-floral Nectaries, Water Stomata, Guttation, Internal Secretory Cells, Idioblasts, Cystoliths vs Raphides, Secretory Ducts and Cavities in Plants, Lysigenous vs Schizogenous Cavities in Plants, Laticifers in Plants, Articulate and Non-articulate Laticifers, Articulate Anastomosing and Articulate Non-anastomosing Laticifers, Chemical Composition of Latex and many more…

Learn more: Lecture Note in Secretory Tissue in Plants

Please be patient to load the online PPT preview

You can DOWNLOAD the PPT from the download link below the preview…

Continue reading

Botany lecture notes

Secretory Tissue System in Plants (Structure, Classification and Functions + PPT)


secretory cells

Secretory Cells and Tissues in Plants
(Structure and Classification of Secretory Tissue System in Plants with Examples)

What are plant secretions?

Most of the plants release many substances from their cell cytoplasm to the exterior and they are called as Plant-secretions. Among these secretions, some are beneficial to the plant and some are not. The beneficial substances secreted from the plant parts are called as secretions. The chemical composition of plant secretions highly varies. The secretions may be water, nectar, salt, tannins, resins, latex, gums, digestive enzymes, hormones etc.

Secretory Cell/Tissue

Cells or tissue associated with or facilitate the secretion is termed as the secretory cell or secretory tissue. The structure, arrangement and the origin of secretory cells/tissues highly varies.

Classification of Secretory Tissues

Ø  The secretory tissue is broadly classified into two categories based on their position in the plant body. They are

(I). External secretory tissue

(II). Internal secretory tissue

Continue reading

Botany lecture notes

Hydathode or Water Stomata–Structure and Functions (Short Notes)


water stomata notes

Hydathode – Water Stomata
(Structure and Functions of Hydathodes)

What are Hydathodes?

Hydathodes are specialized pores (openings) particularly present on the leaf margins, which exudes or secretes drops of water. The exudation of water as drops from the tip or margin of the leaves is called guttation. The process of guttation is facilitated by the hydathodes.

Ø  They are also called as Water Stomata because they structurally resemble stomata and they facilitate guttation (secretion of droplets of water from the pores of plants).

Ø  Hydathodes are commonly found in Angiosperms, especially in grasses.

Ø  They are also present in some other plants such as water hyacinth, balsam, roses, Hibiscus and rarely in some non-angiospermic plants.

Continue reading

Botany lecture notes

Nodal Anatomy of Angiosperms: Unilacunar, Trilacunar and Multilacunar Node with Examples


Classification of Nodes in Plants

Nodal Anatomy of Plants with Diagram
(Leaf Gap, Leaf Trace: Unilacunar, Trilacunar and Multilacunar Nodes in Angiosperms)

Anatomy of Nodal and Inter-nodal Region are Different:

The stem of plants is differentiated into nodes and internodes. The anatomical features of the nodal region are quite different from that of the inter-nodal region. This anatomical difference is due to the presence of Vascular Supply to the leaves and branches from the main vascular cylinder of the stem.

Nodal Region of Higher Plants Posses Leaf Gaps and Leaf Traces

Each leaf that originates from the node, of higher plants possesses vascular tissue and these vascular tissues of the leaves are connected to that of the stem. A vascular strand that extends between the vascular cylinder of stem and the base of the leaf is called Leaf Trace or Foliar Trace. Even if the leaf trace possesses both xylem and phloem, the relative amount of xylem will be more in the leaf trace than phloem. Moreover, the proximal portion, (portion near the vascular cylinder of the stem) contains only the xylem. Whereas, the distal end of the leaf trace (near to the leaf base) contains both xylem and phloem. Leaf trace helps to transport water and minerals from the xylem to the leaf lamina for photosynthesis. The circulation of photosynthetic products from the leaf lamina to the phloem of the stem is also facilitated by the phloem strands in the leaf traces.

Continue reading