BIOL 215 Lecture Notes - Lecture 7: Lophotrochozoa, Blastula, Hydrostatic Skeleton
Document Summary
Choano agellates more related to animals than plants. Up to 390 species or more of different land plants. Certain plant features re ect transition of aqueous environment to land. Land plants evolved from green algae 480 m. y. a. Similar types of pigments: chlorophyll a & b and yellow orange carotenoids alpha & beta. Evolved into organisms which most cells are somatic (formed body cells) and only few were reproductive. Land plants also referred to as embryophytes (zygote develops within archegonium). Land plants have alternation of generation: gametophyte (haploid) and sporophyte (diploid). The alternation can shift between either where one is more dominant. 4 major evolutionary inventions in plants: origin of plants: alternation of haploid/diploid, stomata, cuticle, vascular lineage: vascular system, lignin, true leaves and roots, seed lineage: seeds and pollen, flower lineage. Paraphyletic group: liverworts, mosses, club mosses, and hornworts. Lack vascular tissue & true roots to transport water and nutrients. Thrive in damp places, but can withstand drought.
