Plant Diversity Flashcards
Chapter 29
what is the closest relative of land plants?
green algae called “charophytes”
what four characteristics do land pants share with ONLY charophytes
1) rings of cellulose-synthesizing complexes
2) peroxisome enzymes
3) flagellated sperm with similar structure
4) formation of phragmoplast
what’s a phragmoplast?
microtubules formed along the midpoint during division
why are charophytes considered the closest living relative between plant and algae?
similarities between nuclear and chloroplast genes
what is sporopellenin?
layer of polymer that prevents zygotes form drying out in charophytes and is also found in plant spore walls
what happened when charophytes moved onto land
- unfiltered sun
- more plentiful CO2
- nutrient-rich soil
- few herbivores and pathogens
what challenged did land present?
lack of structural support, scarcity of water
what five traits appear in nearly all land plants but are absent in the charophytes
1) alternation of generations and multicell embryos
2) walled spores produced in sporangia
3) multicellular gametangia
4) multicellular embryo
5) apical meristems
what is alternation of generations?
plants alternate between two multicell stages, the reproductive cycle is alt of gen.’s
what is a gametophyte?
haploid; produces two haploid GAMETES via MITOSIS
what is a sporophyte?
fusion of gametes produces a diploid sporophyte which produces haploid SPORES via MEIOSIS
what are placental transfer cells?
they transfer the nutrients from parent to embryo
what are land plants called embryophytes?
the dependency of the embryo on the parent
where do sporophytes produce spores?
sporangia
what are sporocytes?
diploid cells that undergo meiosis to generate haploid spores
what organs are used to produce gametes in plants?
gametangia
male gametangia? female gametangia?
male: antheridia
female: archegonia
what are apical meristems?
plants sustain continual growth there and the apical meristems differentiate into various tissues
what’s a cuticle?
a waxy covering of the epidermis
what’s mycorrhizae
symbiotic associations between fungi and land plants that may have helped plants without true roots to obtain nutrients
fossil evidence says plants were on land how long ago?
475 million years ago
non-vasc plants
bryophytes
- liverworts
- mosses
- hornworts
seedless vasc plants
- lycophytes (club mosses)
- monilophytes (ferns)