400mya Angiosperms and plant anatomy Million years of evolution: Cooksonia Practical # 3 Mid-term evaluations (lab 6 of 10) Lecture Scavenger Hunt Turn in cladistics worksheet p 123-4 Next week: Last lab practical Angiosperm
Paleo plant and insect interactions
Insects and plants evolved together Older Younger
time Rapid origin
The unique character of angiosperms is that the ovules are completely enclosed in a carpel 1. gametophytes only a few cells 2. immotile sperm- carried to ovule by pollen tube 3. No “spores” because reduced gametophyte
Extinct http://www.pbs.org/wgbh/nova/flower/anat-flash.html Controversy about its floral morphology interpretation http://www.pbs.org/wgbh/nova/flower/
Knowing the flower anatomy…let’s review the fossil record of earliest angiosperms keep in mind:
To date, the origin of the angiosperms remains controversial
No consensus about the ancestral relative
Molecular evidence suggest a Jurassic origin (>150 Ma), but the oldest fossils is early Cretaceous (~125 Ma)
MORE INFO: http://www.mobot.org/mobot/research/apweb/welcome.html
UF grad student found this one!
Many early flowers are related to living Angiosperms families
Pollination of ‘primitive’ flowers
Flowers adapted for pollination by "smart" insects
Insects can see uv light
Insects can see uv light
What pollinates these?
Wind-pollinated flowerssecondarily derived in Angiosperms -- flowers are green, small, and often lack petals. Wind pollinated flowers of deciduous trees species open in early spring – why?
Pick the Pollinator http://www.pbs.org/wgbh/nova/flower/pollinator.html
Plant parts Take a look…
Primitive vs Derived characters http://botany.csdl.tamu.edu/FLORA/tfplab/primder.htm
Fruit and seed dispersal
Don’t forget… Also: ichthyochory
What disperses these?
Pleistocene extinction Gomphothere Late Pleistocene Extinctions – 13,000 years ago, N & S America
“Re-wilding of N. America?”
Angiosperms often used for medicine – why? Preparing ayahuasca
3 clades A. Monocotyledones (monocots) B. Magnoliids C. Eudicotyledones (dicots)
Generalized distinguishing characteristics:
A comparison of monocots and dicots -- know this for lab practical Lab exercise – can you tell them apart?
MONOCOTS All flesh is grass” -- Isaiah Grasses evolved directly with mammals
Storage organs A. white potato demo - modified stem B. green onion demo - leaves modified for storage C. celery - leaf petiole modified D. sweet potato demo - storage root E. carrot - root stores sugars
Principal Biological Concepts this lab: A. Angiosperms as dominant plant taxon. B. Ovules enclosed within two integuments and a carpel wall. C. Structure and function of flowers, and importance of pollinators. D. Carpel wall may ripen as pericarp = fruit. E. Monocots versus dicots F. Double fertilization. G. Plant tissues. H. Primary and secondary growth. I. Structure and function of shoots, roots, and leaves.
To study for next lab practical Moncots vs dicots Flower parts Leaf structures Stem structures, xylem vs phloem, monocots vs dicot vasculature Root tissues & functions Xylem vs phloem
Complete Plant Cladistic Exercise A. Follow directions in Plant Cladistics data sheet (pp. 123-124). B. Complete the cladogram and hand in before you leave.