Evolution of Plantae Flashcards
What are the characteristics of the plant
- Uses photosynthesis to gain energy
- multicellular
reproduce through alternation of generation
What is a photosynthesizer
earth prokaryotes that use photosynthesis to generate sugar
What is a cyanobacteria
- bacterium
- first to use chlorophyll
- chloroplast of today
What is the endosymbiotic theory
eukaryotic cell engulfs a cyanobacterium
- cyanobacterium is used as an energy factor
What is the primary endosymbiotic theory
a eukaryotic cell engulfs a cyanobacterium –> becomes a symbiont
What is the secondary endosymbiotic theory
a eukaryotic cell engulfs cyanobacterium symbiont –> becoming a new symbiont
What are the 8 barriers to adapting to life on land
- Desiccation
- gases are absorbed differently
- reproduction
- buoyancy
- temperature fluctuations
- more light
- dissolved minerals in water
- Harmful UV light
What is the desiccation barrier and the plant’s adaptation
- aquatic organisms dry out in open air
- smaller organisms dry out faster than larger ones because of the surface area
- org. cannot be waterproof
- on epidermis, developed multiple cell layers –> wax layer + evolved roots/roots-like structure to direct movement of water into the body
What is the gas barrier and its adaptation
- need a new gas exchange to take air out of air
- evolved the stomata: specific pores that allow entering of gas (can be closed or open)
What is the reproduction Barrier and its adaptation
aquatic organisms relied on water to facilitate reproduction
- evolved spores and seeds but only germinate when exposed to water
What is the buoyancy barrier and its adaptation
- water and water pressure supports the body tissue structure
- evolved strong fibers and compounds –> lignin, cellulose –> skeleton of plant
What is the temperature fluctuation barrier and its adaptation
- water has slow and little change
- land has quick and large changes
- cell layers & roots helps plant survive extreme temperature fluctuations
What is the more light barrier
water filters out wavelength of light where only certain wavelengths penetrate in deep water
What are the mineral barrier and its adaptation
need a way to supplement nutrition loss
- roots take mineral out of soil and some plants can take nitrogen out of the air
What is the UV radiation barrier & its adaptation
- most Important!
- water could filter UV light, protect sea life but before photosynthesis, there was no ozone layer
- with photosynthesis, ozone layer –> protected from UV radiation
What is the soil of today
- small stones made through chemical weathering of solid rocks
- rich in organic matter
- minerals and water
What is a symbiont
Any organism living in a symbiosis with another organism –> mutually beneficial relationship
Green algae before plants
adapted to freshwater concentrated along coasts. since exposed to dry conditions through tidal movements –> led to adaptations which allowed their descendants to move on to land
What are the 4 terrestrial groups of plants
- seedless non-vascular plants
- seedless vascular plants
- gymnosperms
- angiosperms
What are the characteristics of seedless-non-vascular plants
- first terrestrial group to have evolved from green algae
- 3 main groups: liverworts, mosses, hornworts
- first appearance of terrestrial growth forms & multicellular organisms
- reproduce by spores - gametophyte dominant
- require moist environments
What are the characteristics of seedless vascular plants
- 4 main groups: ferns, horsetails, club mosses, whisk ferns
- reproduce by spore - sporophyte dominant
- have vasculature, roots, many distinct leaves & stems
- moist environment
What are the characteristics of gymnosperms
- 4 main groups: cycads, gingkoes, conifers, gnetidae
- reproduce by seeds - sporophyte present
- have vasculature, secondary growth, roots, leaves, stems
- dry environments
What are the characteristics of angiosperms
- most dominant plant groups
- reproduce by seeds where sporophyte is dominant
- have vasculature, secondary growth, flowers, roots, leaves, stems
- first group that went back to water
approximate evolutionary history
450 million years
