BIOL 1F90 Lecture Notes - Photosynthetic Pigment, Accessory Pigment, Hornwort
11 Apr 2014
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Document Summary
Chapter 28 plants and the conquest of land. What are plants: eukaryotic, primarily photosynthetic organisms that mostly live on land an display many adaptions to life in terrestrial habitats, most likely evolved from aquatic algal ancestors (eg. , freshwater green algae known as charophyceans) Ancestry: monophyletic, kingdom plantae, probably originated from a single common protist ancestor, ancient relatives of modern-day chara or coleochaete (both are complex. Charophycean green algae) probably gave rise to the land plants (embryophytes) Charophyceans and land plants share photosynthetic features: plastids are green, main photosynthetic pigment is chlorophyll a, green accessory pigment is chlorophyll b, orange accessory pigment is beta-carotene, storage of polysaccharide starch in plastids. Charophyceans and primitive land plants share reproductive features: flagellate sperm. In charophyceans a layer of a durable polymer called sporopollenin prevents exposed zygotes from drying out: the accumulation of traits that facilitated survival on land may have opened the way to its colonization by plants.
