BIOL108 Lecture Notes - Lecture 20: Gymnosperm, Viridiplantae, Bog Body

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Richard Moses

Document Summary

Topic 6 - plant diversity, evolution, and life cycles. First plants ordo(cid:448)i(cid:272)ia(cid:374) (cid:894)(cid:1008)(cid:1011)(cid:1009) (cid:373)(cid:455)a(cid:895: vascular tissue iluria(cid:374) (cid:894)(cid:1008)(cid:1006)(cid:1004) (cid:373)(cid:455)a(cid:895) Phylogeny - about 40 000 extant species plus 250 000 species with flowers: nonvascular, vascular, seedless, seeded. Starch in chloroplasts: streptophyta - clade of charophytes and embryophytes (plants). Sporopollenin de(cid:272)a(cid:455)-resistant biopolymer; protects zygote in charophytes. Zygote retained in multicellular haploid (for protection: oogamy has e(cid:448)olved independently in many different clades, charophytes - sister group to plants (type of green algae; commonly called stoneworts); haplontic. Show more care towards their embryos: colonized land (came from an aquatic ancestor, many derived traits are characteristics associated with terrestrial instead of aquatic conditions, need physical support more than aquatic organisms do. Structural support - stems, bark, lignin, waxy cuticles: vascular tissue - xylem & phloem (only in vascular plants) Stomata - for gas exchange and preventing water loss.