Unit III: Archaeplastida Flashcards
What are the Land plants on the ToL?
- Bryophyta (mosses)
- Polypodiosida (ferns)
- Gymnosperms
- Angiosperms
In the transition to land of land plants what were advantages?
- More resources for photosynthesis: light and carbon dioxide
Cuticle
watertight sealant that prevents water loss
Stoma
(Stomata) pores that can open and close and control gas exchange
Flavonoids
UV absorbing compounds that prevent DNA damage
Apical meristems
undifferentiated cells that proliferate (grows) throughout life
What are the defining traits of land plants?
- Cuticle
- Stomata
- Flavonoids
- Apical meristems
Sporophyte
– Multicellular and diploid
– Produce spores by meiosis
Gametophyte
– Multicellular and haploid
– Produce gametes by mitosis
Bryophyta (mosses) characteristics
- Most common in moist forests
- Anchored by rhizoid (precursor to roots)
- Lack vascular tissue (tubes of water in body)
- Gametophyte-dominated alternation of generations
- Homospory
- Water is needed to move gametes
What are the 2 types of tissue in alternation of generations?
- Sporophyte
- Gametophyte
What are the defining traits of Bryophyta?
- Rhizoid
- Gametophyte-dominant life cycle
What was challenge faced by Vascular plants in their transition to land?
- Gravity:
- Vascular tissue (accompanied by roots)
- Elaboration of vascular tissue with two types of cells:
a) Tracheids
b) Vessel elements
Tracheids
secondary cell walls supported by complex polymer lignin (Polypodiopside, Gymnosperms, Angiosperms)
Vessel elements
wider Tracheids, with gaps for more efficient water movement (Angiosperms)