Lecture 12 BIO 311D 2nd Edition Outline of Last Lecture I Macroevolution II Data for Phylogenetic Analysis III Human Evolution Outline of Current Lecture I Eukaryotic diversity and the origin of plant kingdom II Big challenge for early plants life OUT of the water III Plant vegetative organs leaf stem root Current Lecture I Eukaryotic diversity and the origin of plant kingdom We classify eukaryotes into 3 major kingdoms Fungi Animals Plants plus a mixed complex known as Protista Protists include amoebas euglenas ciliates sporozoans dinoflagellates diatoms green algae red algae and brown algae What traits would you use to build a phylogeny of these major eukaryotic groups DNA sequences life cycle reproductive traits etc Slime molds are Protists that are haploid during most of the life cycle During their feeding stages they are single celled amoebas In asexual reproduction the haploid cells aggregate and form a stalked spore forming structure Spores germinate into new amoebas Fungi are made up of elongate threads called hyphae in a mass collectively known as mycelium They eat through absorption in many forms there is an n n stage called the dykaryon Comparing the multicellular eukaryote kingdoms Plants Animals Fungi Life cycles Animals Generally haploid stage is not multicellular Plants alternation of generations multicellular n and multicellular 2n Members of the Plant Kingdom seem to form a monophyletic group based on these shared derived traits that are not found in algae protists Multicellular reproductive organs Multicellular embryos retained on parent Apical meristem continuous mitosis Which type of algae is the sister group to Plants and how do we know Traits to compare cell wall material food storage molecule and specific photosynthetic pigments Plants retain multicellular embryos on the parent plant Plants have multicellular reproductive organs Plants have apical meristems zones of continuous mitosis at tips of roots and shoots II Big challenge for early plants life OUT of the water When plants first colonized land habitats what were the new opportunities evolutionary advantages More sunlight CO2 would be everywhere less predators Disadvantages lack of water UV radiation too hot III Plants vegetative organs leaf stem root Leaf photosynthesis Stem transport and support Root anchor and absorb
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