BIO120H1 Lecture Notes - Lecture 17: Monstera Deliciosa, Convergent Evolution, Outline Of Life Forms
36
BIO120H1 Full Course Notes
Verified Note
36 documents
Document Summary
Lecture 17: physiological ecology of plants: more tradeoffs. Stresses on plants are especially challenging because they can"t evade stress by moving: plants solve problems by growth & development, not behaviour, so carbon balance is central. Tradeoffs on photosynthesis: compromises involving 3 necessities: light, temperature, water: adaptations to an extreme habitat: deserts, adaptations to an extreme lifestyle: epiphytes. Green stick : photosynthetic bark on trunk and ranches, can grow without incurring heat load and water loss through leaves. Too much water loss through leaves reduction of leaves: reduction of leaves leads to lesser capacity for photosynthesis, microphylly, condition of having small leaves. Santa rita prickly pears: don"t make leaves, modified stem. Leaves modified into thorns repurposed into adaptation to repel herbivores: flattened to provide more area for photosynthesis, cactus pads oriented on a n-s axis early and late in the day. In the middle of the day, oriented e-w. Cacti root systems: extensive root systems, adaptation for harvesting water.
