Leaf structures - Plant Science - Lecture Slides, Slides of Biology

Download Leaf structures - Plant Science - Lecture Slides and more Slides Biology in PDF only on Docsity! Concept Study of the Leaf structure & Phyllotaxy in plants. Docsity.com Purpose Awareness about the structure of a typical leaf & the types of Phyllotaxy in plants for their mode of arrangement Docsity.com How Tech. Non Tech. Teacher Student Activity: Session of Q/A on leaf structure & Phyllotaxy Study the structure of Leaf through original specimens. Look at the venation in leaf specimens & study it. Q/A on monitor Leaf specimens Active through explanation Active Docsity.com What Else Tech. NonTechni- cal Teacher Student 1. Collect some more leaf specimens to identify their venation, from your neighboring area . 2. Categories different plant as monocot & dicot on the basis of venation. 3. Find out that all the leaves have all the three parts or not. If not, note down the missing parts. - Collection of leaves samples Passive Active Docsity.com Definition of Leaf Leaf is the flattened outgrowth of Stem or a branch that develops at node & has a bud in it’s axil. These are the dissimilar organs & are meant primarily for Photosynthesis, Respiration & Transpiration. Docsity.com Petiole The part of leaf that connects the lamina with stem, is called leaf petiole. Some time a leaf may not have a petiole, such leaves are called – Sessile otherwise the leaf is called Petiolate. Docsity.com Lamina It is the flat, expended & broad part of leaf with framework of veins & veinlets. The lamina is the most important part of the leaf as it is the seat of food manufacturing in plant. Docsity.com Phyllotaxy It is the mode of arrangement / distribution of leaves on stem or it’s branch. Phyllotxy ensures that leaves may receive maximum sunlight for photosynthesis. Phyllotaxy Alternate Opposite Whorled Docsity.com Opposite Decussate Here pairs of leaves at each successive node are placed at right angle to each other. Eg. Ocimum, Calotropis etc. Docsity.com Oposite Superposed Here pairs of leaves at each successive node are placed over each other in same plane. Eg.Eugenia,Quisqualis etc. Docsity.com Whorled Phyllotaxy In this type more than two leaves are present at each node, forming a whorl. Ex. Oleander, Alstonia etc. http://www.umanitoba.ca/faculties/science/biological_sciences/lab10/biolab10_4.h tml#Structure Docsity.com