Leaf structures
- 1. Lesson PlanLesson Plan BIOLOGYBIOLOGY Std. -XStd. -XII
- 2. Concept Study of the Leaf structure & Phyllotaxy in plants.
- 3. PurposePurpose Awareness about theAwareness about the structure of a typicalstructure of a typical leaf & the types ofleaf & the types of Phyllotaxy in plants forPhyllotaxy in plants for their mode oftheir mode of arrangementarrangement
- 4. CategoryCategory & Time& Time MediumMedium 40-45 minutes40-45 minutes
- 5. Learning OutcomesLearning Outcomes Student’s awareness aboutStudent’s awareness about the –the – * Typical leaf structure* Typical leaf structure * Essentiality of various* Essentiality of various leaf parts in a plantleaf parts in a plant * Familiarity about* Familiarity about Phyllotaxy in plantsPhyllotaxy in plants
- 6. Lesson flow Technica l NonTeh n-ical Teache r Student Why To have an idea about the importance of leaf parts in a typical leaf. To catagorise the plants on the basis of phyllotaxy, -- Verbal com muni catio n Active Partly active
- 7. What Tech.Tech. NonNon Tech.Tech. TeacherTeacher StudentStudent Module on Bhartiyavi dya Original leaf Specimens Active Active Definition of Leaf M Parts of typicalLeaf M Importance of these parts M Definition of Phyllotaxy M Types & subtypes of Phyllotaxy H
- 8. How Tech.Tech. NonNon Tech.Tech. TeacherTeacher StudentStudent 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 onQ/A on monitormonitor Leaf specimens Active through explanation Active
- 9. Question sessionQuestion session Q. Give the definition of leaf.Q. Give the definition of leaf. Q. What do you call the structure by which leaf is attached atQ. What do you call the structure by which leaf is attached at plant?plant? Q. Give the technical term for the mode of arrangement ofQ. Give the technical term for the mode of arrangement of leaves on plant.leaves on plant. Q. How many types of arrangement of leaves in plants areQ. How many types of arrangement of leaves in plants are there/there/
- 10. What Else Tech.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 ofCollection of leaves samplesleaves samples PassivePassive ActiveActive
- 11. 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.
- 12. Parts of the Leaf 1. Leaf Base2. Petiole3. Lamina more
- 13. Leaf Base The part of leaf attached to the stem or branch is called- Leaf base. It protects a Bud in it’s axil.
- 14. 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.
- 15. 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.
- 16. 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
- 17. Alternate Phyllotaxy In such case only one leaf is attached at each node. The leaves are so arranged that a line drawn on the stem through the leaf bases will take a spiral course. Ex. Hibiscus, Brassica etc.
- 18. Opposite Phyllotaxy In such case two leaves are present at each node, standing opposite to each other. It is of two subtypes - Opposite decussate Opposite superposed
- 19. Opposite Decussate Here pairs of leaves at each successive node are placed at right angle to each other. Eg. Ocimum, Calotropis etc.
- 20. Oposite Superposed Here pairs of leaves at each successive node are placed over each other in same plane. Eg.Eugenia,Quisqualis etc.
- 21. 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
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