BIOA02H3 Lecture Notes - Lecture 2: Spermatozoon, Bryophyte, Lycopodiophyta
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BIOA02H3 Full Course Notes
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3 kingdoms: bacteria, archaea, eukaryotes; all come form a common ancestor. Contain liveworts (6000), mosses (x2, 12,000), hornworts (100) Delicate don"t fossilize well (cid:0) unsure when they were born . Don"t have a cuticle: easy uptake & loss of water along the whole surface, loses h2o over leaf easily (cid:0) typically live in moist habitats (spermatozoids!, can survive total desiccation (water loss); used to losing h2o. Lack of vascular system: no specialized transport for nutrients/water, can"t transport water/nutrients very efficiently (passive transport) (cid:0) typ. small, must be close to moist environments. Antheridium incl. sperm; male sex system. 1 haploid egg; femal sex organ; hidden w/in plant. Spore capsule (2n) stores spores (n) Fertilization depends strongly on water: sperm = an active swimmer; need a film of h2o to travel efficiently down the style. Two mobile life cycle phases: water-dependent dispersal = sperm (cid:0) ovule (egg, wind-dependent dispersal = spores blown away from spore capsule.