A beginner-to-intermediate tour of plant internal structure, from tissue systems to dicot and monocot roots, stems and leaves
This course introduces the internal structure and functional organisation of higher plants, beginning with the three tissue systems — epidermal, ground and vascular. It then examines the transverse anatomy of dicotyledonous and monocotyledonous roots and stems, and the vertical anatomy of dorsiventral and isobilateral leaves. Throughout, the course stays close to the chapter's terminology and examples, including stomatal apparatus, open and closed vascular bundles, casparian strips, bulliform cells and secondary growth.
The lessons are arranged as a connected sequence. Full lesson content and assessments can be generated and published separately.
Introduces plant anatomy as the study of internal structure and explains how cells are organised into tissues and tissues into organs. Notes that organs differ internally and that monocots and dicots are anatomically different, with internal structures showing adaptations to diverse environments.
Describes the epidermal tissue system as the outer-most covering of the plant body, made of epidermal cells, stomata and epidermal appendages. Covers the single-layered parenchymatous epidermis, the cuticle, stomatal structure with guard and subsidiary cells, and the distinction between root hairs and trichomes.
Explains that all tissues except epidermis and vascular bundles make up the ground tissue, composed of simple tissues — parenchyma, collenchyma and sclerenchyma. Notes where parenchyma occurs in primary stems and roots and that leaf ground tissue is mesophyll.
Describes the vascular system as complex tissues — phloem and xylem — that together form vascular bundles. Explains open versus closed bundles based on cambium, radial versus conjoint arrangement, and the usual position of phloem on the outer side of xylem in conjoint bundles.
Follows the transverse section of the sunflower root from epiblema and root hairs through cortex, endodermis with casparian strips, pericycle, conjunctive tissue, xylem and phloem patches, and pith. Introduces the stele as all tissues inside the endodermis.
Compares the monocot root with the dicot root: similar layers of epidermis, cortex, endodermis, pericycle, vascular bundles and pith, but usually more than six (polyarch) xylem bundles, a large well-developed pith, and no secondary growth.
Describes the young dicot stem: epidermis with cuticle, trichomes and stomata; a three-zoned cortex (hypodermis, parenchyma, starch sheath); semi-lunar sclerenchymatous pericycle; medullary rays; vascular bundles in a ring, conjoint, open and with endarch protoxylem; and a central pith.
Describes the monocot stem: sclerenchymatous hypodermis, scattered vascular bundles each surrounded by a sclerenchymatous bundle sheath, and a large parenchymatous ground tissue. Bundles are conjoint and closed; peripheral bundles are smaller; phloem parenchyma is absent and water-containing cavities occur within bundles.
Describes the vertical section of a dorsiventral leaf through the lamina: adaxial and abaxial epidermis with conspicuous cuticle, mesophyll differentiated into palisade and spongy parenchyma, and vascular bundles in veins and midrib surrounded by thick-walled bundle sheath cells.
Describes the isobilateral leaf: stomata on both surfaces and mesophyll not differentiated into palisade and spongy parenchyma. Explains bulliform cells in grasses and how turgid versus flaccid bulliform cells affect leaf curling, and notes that parallel venation is reflected in near similar vascular bundle sizes. Closes with the chapter summary comparing monocots and dicots.
Use the lesson order as your study path, then return to the matching quiz focus before moving ahead.
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