BIOl 152 1st Edition Lecture 13 Outline of Last Lecture I Plant tissue II Leaf function III Stomata IV Vascular tissue V Substance Transport VI Transfer of Xylem Sap VII Sugar Transport system Outline of Current Lecture I Plant Diversity II Basic Plant Life Cycle III Nonvascular plants IV Vascular plants V Seed Plants Current Lecture I Plant Diversity Plantae are diverse organisms and most closely related to the Charophytes otherwise known as green algae This taxon is paraphyletic and mostly aquatic whereas the Plantae are most terrestrial organisms and monophyletic Plants contain several synapomorphy traits such as containing a cuticle an apical membrane multicellular sporophyte and walled spores A cuticle is a waxy layer on top of the plant skin that protects the plant and prevents water loss An apical membrane is similar to a plasma membrane and functions to protect the plant from the dangers in the environment and prevents water loss A sporophyte is important for the plants life cycle and is essential in making spores Walled spores are a coat or wall that protects the inside of the plants from water loss II Basic Plant Life cycle The plant life cycle contains alternating generations where it alternates from the sporophyte generation to the gametophyte generation The life cycle begins when a diploid sporophyte undergoes meiosis and produces a haploid spore The haploids are transported by dispersion from the wind or animals There the haploid spore undergoes mitosis producing a These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute gamete The gamete undergoes fertilization where the sperm is released by the stimulation of rain Then finally a fertilized gamete produces a sporangium III Nonvascular Plants Nonvascular plants are also known as Bryophytes and are not monophyletic These plants do not contain vascular tissues are relatively small in size lack roots instead they have rhizoids hairy like structures that increase the surface area The dominant generation in the life cycle is the gametophyte generation Water is required for the fertilization of gametes Some examples of nonvascular plants are mosses liverworts and hornworts IV Vascular Plants Vascular plants are a monophyletic group with the synapomorphine being that they contain vascular tissues Some evolutionary trends are a reduction in size independence of the gametophyte and an increased role of the sporophyte Because of these evolutionary trends the sporophyte is the dominant generation in the life cycle Similar to the nonvascular plants water is required for fertilization Examples are Lycophytes Ferns and horsetails all of which do not produce seeds Lycophytes are commonly referred to as club mosses most are extinct and the living species are usually low growing These plants require a moist environment and the leaves and roots are convergent similarity with the seed plants The dominant generation is the sporophyte The ferns and horsetails are often used as houseplants These contain leaves with a branched vascular tissue and roots a homologous characteristic to seed plants The life cycle for these plants closely resembles the common plant life cycle but is dominated by the sporophyte generation V Seed Plants This is a monophyletic group and the synapomorphines are that they contain seeds the gametophyte develops in the sporophyte pollen not water is required for fertilization they contain ovules and they contain specific seed dispersal structure Like the vascular plants the seed plants contain a sporophyte dominated life cycle Examples of seed plants are Gymnosperms and angiosperms Gymnosperms contain seeds that are enclosed in ovaries The life cycle begins when the cells in a male gametophyte a microsporangium undergo meiosis which then create microspores and then these produce pollen after undergoing mitosis The female gametophyte the megaporangium undergoes meiosis and produces megaspores which then go through mitosis to produce female gametophytes