BIOL 225 Lecture Notes - Lecture 15: Casparian Strip, Phyllotaxis, Symplast
11 Mar 2018
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Document Summary
Plant movement on land: what would be the problems that algae would face if it came out onto the land, it would dry out, have no support and no transport system. Plants have the cuticle (waxy layer) that keeps them from drying out. Adaptations in each species represent compromises between enhancing photosynthesis and minimizing water loss. Plants have plastic responses that vary with different growing conditions, heritable genetics, age and evolutionary fitness. Water conduction is one direction (root to shoots) sugar transport can be done in any direction. Recall: stems serve as conduits for water and nutrients and as supporting structures. Positive correlation between water availability and leaf size (i. e. more water = bigger leaf: phyllotaxy: arrangement of leaves on a stem (specific to each species). Most angiosperms have alternate phyllotaxy with leaves arranged in a spiral (137. 5 ) Vertical leaves are preferred in sunny conditions because less damage by sun and allows light to reach lower leaves.
