Seedless Plants - Ch. 25 Flashcards
how many years ago did the green algae and land plants share an ancestor; what supergroup are they included in?
1 billion years ago; supergroup archaeplastida
what two lineages did ancestral green algae give rise to?
chlorophytes and streptophytes
what did the chlorophytes give rise to?
aquatic algae
what did the streptophytes give rise to?
gave rise to land plants. group includes the charophytes, which includes the pond plants, and the embryophytes which includes the embryophytes
chlorophytes
microscopic, 2 anterior flagella, most are haploid, reproduces both sexually and asexually, not haplodiplontic, always unicellular
streptophytes
eukaryotic, autotrophic, starch food storage as cellulose, alternations of generations life cycle, asexual and sexual reproduction, capture light and fix CO2
did chlorophytes make it to land?
no
did the charophytes make it onto land?
yes, they are the sister group to all land plants
charophytes
clade of the streptophytes, also green algae, distinguished from chlorophytes by close phylogenetic relationship to land plants, have haplontic life cycles, has 2 clades: charales and colechaetales
what traits do charophytes share with land plants?
homologous chloroplasts, meaning they utilize chlorophyll a and accessory pigments chlorophyll b and carotenoids, cellulose in cell wall, and store excess sugars as starch
characteristics of embryophyes
waxy cuticle, gametes protected in sex organs (gametangia), embryo protected by the parent
what are the adaptations to terrestrial life?
protection from desiccation with the addition of a waxy cuticle and stomata, moving water using tracheids, dealing with UV radiation caused mutations, haplodiplontic life cycle
what are the ecological roles of bryophtes?
contribute to biodiversity in all terrestrial ecosystems, carbon storage, and the colonization of rocks and soil
what do soil crusts do?
provide micro-habitats, the crust communities are algae, lichen, moss, and bacteria. the soil crusts stabilize soil, reduce erosion, and provide a nitrogen fixing bacteria and micro-organisms
bryophytes
closest living descendants of first land plants, called nontracheophytes because they lack tracheids, they uptake nutrients and water through diffusion, mycorrhizal relationships to enhance water uptakes, highly adaptable, 3 clades: liverworts, mosses, and hornworts, gametophyte is haploid and sporophyte is diploid, require water for sexual reproduction
thallus
A plant body that is not differentiated into stems and leaves, and lacks true roots and a vascular system. The plant body may be round with extended leaves or may be flat and ribbon-like.
rhizoids
anchor the plant, Hair-like structures on the thallus similar to roots
dichotomous branching
Branching into two arms, or forking into two
antheridium
Male sex organ -club shaped which contains androcytes. Each androcyte changes to a small, motile, biflagellate antherozoid (spermatozoid).
archegonium
Female sex organ – flask-shaped. Contains an egg or oosphere.
zygote
The result of fertilization by the penetration of the large, non-motile oosphere by the small, motile antherozoid
Liverworts
marchantiophyta/hepaticophyta
have flattened gametophytes with liverlike lobes, form gametangia in umbrella-shapped structures, also can undergo asexual reproduction, no stomata - takes up water on the surface and no cuticle