1 / 12

LEAVES

LEAVES. Photosynthetic organs of plants. Basic Leaf Structure. Axillary bud . Simple – single blade Compound – 2 or more leaflets *Look for petiole & bud 2 kinds: Pinnate Palmate. Leaf Types. Leaf Cross-Section. Leaf Epidermis. Upper and lower surface of leaf covered by epidermis

odeda
Download Presentation

LEAVES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LEAVES Photosynthetic organs of plants

  2. Basic Leaf Structure Axillary bud

  3. Simple – single blade Compound – 2 or more leaflets *Look for petiole & bud 2 kinds: Pinnate Palmate Leaf Types

  4. Leaf Cross-Section

  5. Leaf Epidermis • Upper and lower surface of leaf covered by epidermis • Most cells lack chloroplasts and are transparent • Cells secrete cuticle made of waxy cutin • Many leaves have hairlike trichomes • May reduce water loss • May produce irritants – discourage herbivores

  6. Stomata • Tiny openings flanked by guard cells • Gas exchange; transpiration • Most numerous on lower epidermis of horizontal leaves

  7. Mesophyll • Made of photosynthetic ground tissue • Divided into 2 sublayers: • Palisade mesophyll • Spongy mesophyll

  8. Vascular Bundles • Veins extend throughout the mesophyll • Contains: • Xylem • Phloem • Bundle sheath - 1 or more layers of cells surrounding the larger veins • Made of parenchyma or schlerenchyma cells

  9. MONOCOT Base of leaf wraps around stem in a sheath (lack petiole) Some monocots do not have distinct palisade and spongy layers DICOT Broad flattened blade and petiole Palisade and spongy layer Guard cells shaped like kidney beans Monocot vs. Dicot

  10. LEAF ADAPTATIONS • Cuticle • Placement of stomata • Needles vs. leaves • Length of petioles

  11. Modified Leaves • Spines • Tendrils • Bulbs • Carnivorous

More Related