Chapter 33

Chapter 33 - For gas exchange needed in photosynthesis...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 33 (Leaf Structure and Function) Leaves Broad, flat blade Stalk-like petiole Some also have stipules Small, leaf-like outgrowths from the base Epidermis Covers upper, lower surfaces of leaf blade Waxy cuticle coats epidermis Helps plant survive dry terrestrial conditions Stomata Small pores in epidermis Permit gas exchange for photosynthesis Surrounded by two guard cells Often associated with special epidermal cells (subsidiary cells) Mesophyll Photosynthetic parenchyma cells Palisade Mesophyll Functions primarily for photosynthesis Spongy Mesophyll Functions primarily for gas exchange Leaf Veins Xylem Conducts water and essential minerals to leaf Phloem Conducts sugar produced by photosynthesis to rest of plants Monocot leaves Have parallel venation Eudicot leaves Have netted venation Adaptations for Photosynthesis 1 Most leaves have broad, flattened blade. Efficient in collecting sun’s radiant energy Stomata open during day
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: For gas exchange needed in photosynthesis Close at night to conserve water when photosynthesis is not occurring Transparent epidermis Allows light to penetrate into middle of leaf, where photosynthesis occurs Air spaces in mesophyll tissue Permit rapid diffusion of CO2 and water into (and oxygen out of) mesophyll cells, Transpiration Loss of water vapor from aerial parts of plants Occurs primarily through stomata Rate of Transpiration Affected by enviornmental factors Temperature Wind Relative humidity Effects of Trasnpiration Both beneficial and harmful to plant Trade-off between Co2 and water conservation Leaf Abscission Loss of Leaves As winter approaches in temperate climates At beginning of dry period in tropical climates with wet and dry seasons Complex process Physiological and anatomical changes occur prior to leaf fall....
View Full Document

Page1 / 2

Chapter 33 - For gas exchange needed in photosynthesis...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online