Botany lecture notes

Similarities and Differences between Pteridophytes and Gymnosperms


Gymnosperm vs Pteridophytes

Pteridophytes vs Gymnosperms
(Similarities and Differences between Pteridophytes and Gymnosperms)

Pteridophytes:

Pteridophytes are a group of primitive land plants belongs to Cryptogams. They are the first plant group with vascular tissue for the conduction of water and food materials and hence they are called as Vascular Cryptogams.

Gymnosperms:

Gymnosperms are a group of primitive seed-producing plants of Spermatophytes (Phanerogams). They are ‘Naked-Seed’ Plants characterized by naked ovules (i.e., ovule without the ovary). The ovules of Gymnosperms are borne directly on the surface of the megasporophyl. Since ovary is absent, Gymnosperms do not produce fruits.

Pteridophytes occupy the intermediate position between Bryophytes and Gymnosperms (seed plants). Gymnosperms were believed to be originated from the Pteridophytes in the Devonian period (419 to 359 million years ago) of Paleozoic Era. Pteridophytes and Gymnosperms share many characteristics. In the previous posts, we discussed the General Characters of Bryophytes Pteridophytes and Gymnosperms. In this post, we will discuss the Similarities and Differences between Pteridophytes and Gymnosperms with Comparison Table.

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Botany lecture notes

Classification of Gymnosperms PPT (Chamberlain System – 1934)


Plant Science PPT

Classification of Gymnosperms PPT
(Chamberlain System of Classification of Gymnosperms – 1934)

Classification of Gymnosperms, Outline of the history of Classification of Gymnosperms, Chamberlain System of Classification of Gymnosperms, Class Cycadophyt and Coniferophyt, Order Cycadofilicales (Pteridospermales) Cycdeoidales (Bennettitles) and Cycdales, Order Cordaitales, Ginkgoales, Coniferales and Gnetales.

Learn more: Lecture Note on Classification of Gymnosperms

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Botany lecture notes

Classification of Gymnosperms by Chamberlain (1934)


Classification of Gymnosperms

Classification of Gymnosperms
The Chamberlain System – 1934

Brief history of the classification of Gymnosperms:

There are many systems for the classification of Gymnosperms in the literature. Robert Brown (1827) for the first time recognized Gymnosperms as a separate group of plants. Bentham and Hooker (1883) placed Gymnosperms between Dicots and Monocots in their classification (General Plantarum). Van Tieghman (1898) gave the status of Major Division to the Gymnosperms. Tieghman also divided the whole Spermatophyta (seed plants) into two divisions namely Gymnosperms (Astigmatae) and Angiosperms (Stigmatae). Coulter and Chamberlain in 1912 divided the division Gymnosperms directly into seven orders namely (1) Cycadofilicales, (2) Bennettitales, (3) Cycadales, (4) Cordaitales, (5) Ginkoales, (6) Coniferales and (7) Gnetales.

Classification of Gymnosperms by Chamberlain (1934)

Ø  Chamberlain (1934) divided the Gymnosperms into TWO classes and each class into orders.

Ø  Gymnosperms were divided into TWO classes:

(1).      Cycadophyta

(2).      Coniferophyta

Chamberlain System of Classification

Class I : Cycadophyta

Ø  Class Cycadophyta includes both fossil and living forms.

Ø  The stem is unbranched and stumpy.

Ø  Leaves are large and pinnately compound.

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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.

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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

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