BIOL 110 Lecture Notes - Lecture 1: Vascular Tissue, Gametangium, Cuticle
Document Summary
Plants: chlorophyll b, cellulose, starch, stationary, multicellular, alternation of generations. Alternation of generations: alternation between multicellular haploid and diploid stages in life cycle, sporophytes. Produce 1n spores through meiosis: spores develop into gametophytes (1n) through mitosis, gametophytes. Produce haploid gametes by mitosis, which join with other gametes (fertilization) to form sporophytes. Needing to move water around body of organism. Increased mutation rates: lack of competition/ herbivores. Gametes, zygotes, and embryos are protected within parental tissues: gametes, zygote, and embryo stages are all sensitive to water loss, enclosed in jacketed tissue (gametangia) to reduce desiccation. Waxy cuticle reduces water loss: wax= hard lipid (takes higher temperature to melt than fat, helps solve problem of water loss. Stomata are pores on the surface of plants: closed during hottest part of the day. Function of vascular tissue in plants: xylem - moves and water and minerals, phloem - moves sugars. Signficant events in plant evolution: gametangia, waxy cuticle, vascular tissue.
