UAB BY 124 Exam 1 Questions And Answers With Verified Tests 100% Correct Answers

charophytes - (aquatic) green algae land plants evolved from 3 key traits land plants share with charophytes - 1. rings of cellulose-synthesizing proteins embedded in plasma membrane 2. formation of a phragmoplast (helps form cell wall) 3. structure of flagellated sperm (not all will have this) adaptations enabling plants' move to land: why? - 1. CO2 2. sunlight 3. soil- nutrients 4. fewer predators/pathogens (never been seen before) adaptations enabling plants' move to land: problems? - 1. lack of structural support 2. scarcity of water adaptations enabling plants' move to land: adaptations? - 1. survive periods when not submerged 2. charophytes have a layer of durable polymer (sporopollenin) that prevents exposed zygotes from drying out natural selection - can only act on traits present in population phylogenetic tree of ancestral algae - a. red algae b. chlorophytes c. charophytes d. embryophytes4 derived traits (unique to) of plants - 1. alteration of generations and multicellular, dependent embryos 2. walled spores produced in sporangia 3. multicellular gametangia 4. apical meristem alteration of generations - n (gametophyte) <-> 2n (sporophyte) multicellular, dependent embryos - supported by maternal tissue, placental transfer walled spores produced in sporangia - adaptation multicellular gametangia - through mitosis: female (n) -> eggs (n) male (n) -> sperm (n) archegonia - female gametangia antheridia - male gametangia apical meristem - where growth occurs (up or down) other derived traits of plants - 5. cuticle (waxy covering of the epidermis) 6. stomata (open & close for gas exchange) 7. mycorrhizae (symbiotic relationship between fungi and land plants -> nutrients) 8. secondary compounds (deter herbivores and pathogens) origin and diversification of plants - -evident in fossilized spores & sporophyte (2n) tissue-see image for phylogenetic tree life cycles of mosses & other nonvascular plants: dominated by? - gametophytes (n) 3 phyla of byrophytes (small, herbaceous (non-woody) plants) - 1. liverworts (Phylum Hepatophyta) 2. hornworts (Phylum Anthocerophyta) 3. mosses (Phylum Byrophyta) location of gametophyte (n) & sporophyte (2n) - -can be in close proximity -sporophyte arises from gametophyte life cycle of moss - sporophyte (2n) -> meiosis -> spores (n) -> mitosis -> gametophytes (n) (malesperm and female- egg) -> fertilization within archegonium (sperm has flagella and swims to egg) -> zygote (2n) -> embyro (2n) -> sporophyte (2n) asexual reproduction in mosses - brood bodies