colonization of land Flashcards
Definition of plants
no strong definition yet, many disagreements
4 major groups of land plants
1.mosses (belong to bryophytes)
2.ferns (seedless vascular plants)
3.gymnosperms (seeded vascualr-seeds onn leaves)
4. angiosperms (seeded vascular-seeds in fruits and flowering)
non-vascular plants
-no vascualr tubes
-usually small and found in damp, moist areas
-get nutrients by slowly passing from cell to cell (diffusion)
-bryophytes eg)mosses, liverworts, and hornworts
vascular plants
-have specialized tubes to transport water and food around plant.
-2 types:
1. xylem- water and nutrients from roots to rest of plant
2. phloem-food from leaves to rest of plant
-allows plants to be tall and found on land eg)ferns, trees
which period did bryophytes arise
ordovician period ~475mya
Which plants are embryophytes?
-land plants
-complex multicellular eukaryotes with reproductive organs
-mostly autotrophs but can be heterotrophs
derived traits
traits that appeared by mutation which come from their most recent ancestor
which adaptations allowed plants to move to land
1.adaptations for reproduction
2. preventing dehydration
are algae photosynthetic. if so which algae
brown and green algae
bryophyte contraints
- moist enviornemts bc they have flagellated sperm
- short bc they lack a vascular system, roots, and leaves
key adaptations of bryophytes (5 derived traits of land plants)
- embryophytes-retained their multicelluar embryo and protected
- walled spores-to prevent spore from drying out
3.gamete production in gametangia (protects gametes) - growth by apical meristems (tissues on ends of leaves stems etc.)
- waxy cuticle and stomata (except liverworts. they have stomata like openings that cant open and close. and no cuticle so the plant takes up water over entire surface)
phylum of bryophytes
liverworts, hornworts, and mosses
stomata
pores that open and close by guard cells and exhchange gases. water is also let out by water vapour
gametangia
an organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants.
a gametangium is a haploid structure and formation of gametes does not involve meiosis.
which period did seedless vascular plants rise
silurian period ~420mya
which phylum are included in seedless vascular plants
horsetails, clubmosses, and ferns
key adaptations of seedless vascular plants
vascular tissue-allows for reduced height constraint, structural support and efficent transport of water, nutrients and food