Green Plants – Flashcards

Kingdom of 'green plants'; arose from a charophycean (green algae) Consider: Remember that organisms in the same clade are monophyletic.

predecessor of terrestrial plants; display a zygotic life cycle with a one cell diploid zygote while bryophytes and other plants exhibit a sporic life cycle with alternation of generations

having multicellular haploid (gametophyte) and multicellular diploid (sporophyte) stages, unlike diplontic (humans) in which only the diploid stage is multicellular Consider: Alternation of generations found in plants means one phase of the life cycle is diploid and the other is haploid. Each stage functions as the name implies...gametophyte is production of gamete and sporophyte is production of the spore. Within Bryophytes, contrary to the life cycles of vascular plants, the haploid gametophyte is the dominant generation in mosses and other bryophytes. Sporophytes are generally smaller and depend on the gametophyte for water and nutrients.

due to specialized roots, stems, specialized reproductive features, and increased area for photosynthesis in the leaves Consider: Land plants evolved from freshwater algae. The Charophyta are a sister clade to all the land plants. The Tracheophytes include all the land plants except for the sister clade of Bryophytes (liverworts, mosses, hornworts). A tracheid (where term Tracheophytes is derived) is a specialized vascular cell.

waxy cuticle, spores, stomata (mouth shaped openings which allow water to diffuse out at the same time gas diffusion into an out of the plant is occurring), tracheids (specialized vascular cells that facilitate the transport of water and minerals) Consider: Survival on land for organisms is difficult because of the problem of desiccation.

adaptation for more effective water dispersal within plants Consider: Vascular tissue in plants offers physical support of the plant and transportation of water, minerals, and organic compounds. Bryophytes are the only kind of plants that have NO vascular members.

earliest land plants appeared ~500mya; vascular plants - ~430 mya seed plants - ~365mya Consider: The development of seeds was an adaptation when comparing it to spores because seeds are tougher giving them a higher resistance to pathogens and can remain dormant and survive unfavorable conditions. Also, seed production does not require water as a medium for sperm transport.

liverworts & hornworts Consider: Bryophytes, include liverworts, hornworts, and mosses, are non-vascular plants.

have primitive conducting systems; moss leaves and true leaves both have chlorophyll a and b; although land plants, are still tied to water because of their flagellated sperm produced in antheridia the female gamete (produced in archegonia) of mosses is haploid, has no flagella, is produced by gametophyte generation, and is larger than male gamete

protective covering on spores

cell division at tips of stems and shoots Consider: Early vascular plants grew only by this method

have tallest living specimens

plant (phyla Pterophyta) releases haploid spores during sporophyte (large plant/ dominant stage in life cycle) generation --> gametophytes; comparisons between mosses and ferns is that both kinds of plants have flagellated sperm that have to swim to reach female gamete and both have wind dispersal of spores. But the sporophyte generation is much larger than the gametophyte generation in ferns yet is smaller than the gametophyte generation in mosses and spores are produced in capsules on stalks in mosses but in small structure called sori on the underside of leaves in ferns. Consider: The fern, a seedless vascular plant, requires water for fertilization

burning peat, wood, coal, and petroleum release the carbon dioxide that plants removed and stored in tissue and increases in CO2 triggers temperature rise by retaining solar heat

male gametophytes

first seed plants; includes Coniferophyta, Ginkgophyta, Cycadophyta, and Gnetophyta; produce "naked" seeds since they are not enclosed in fruit

longest surviving group of gymnosperms

used by the following angiosperms: oaks, grasses, and birches Consider: Pollination is the transport of pollen from a microsporangium to a stigma whereas fertilization is the fusion of a sperm with an egg.

this process is unique to angiosperms, consists of fertilization of an egg by one sperm and of the nucleus of an endosperm-forming cell by another sperm, and leads to the formation of a diploid zygote and the typically triploid primary endosperm nucleus

mature ripened ovary containing fertilized seeds

includes embryo (sporophyte), endosperm (food source for embryo), and a protective cover Consider: The advantages of retaining the young sporophyte as an embryo within the parents is to protect it from desiccation, supply it with nutrients, and protect it from pathogens and UV light. Seeds are tough, so they can resist abrasion, remain dormant to survive unfavorable conditions, and do not require water as a medium for sperm transport (as seen in non-seed plants). But when compared to spores, considerably fewer are produced. Fruits are simply ripened ovaries containing seeds.

seed plants produce two kinds of gametophytes; pollen grains are conveyed to female gametophyte by wind or pollinators, sperm reaches eggs by traveling through a pollen tube and a dormant phase is introduced into the life cycle seed plants use meiosis to produce microspores and megaspores Consider: Seed plants include gymnosperms and angiosperms, but only angiosperms have flowers, fruits, and endosperm in seeds.

colorless root-like projections of mosses, liverworts, and hornworts, which anchor them to the substrate

pore-like structures on leaves that open & close depending on environmental conditions thereby regulating intake of carbon dioxide, release of oxygen, and loss of water.

polymer on the leaves of vascular plants that protects them from pathogens

transports water and dissolved minerals upward from the roots to stems & leaves

transports carbohydrates (food) away from green parts of plant to rest of plant