Plant Evolution &
Diversity Overview
LOCAL FLORA – Lecture 01
Dr. Donald P. Althoff
LEC 01
SEEDS & FRUITS (not ___________)
ANGIOSPERMS
Algae-to-Plants: Land Conquered
• _______ or rootlike structures
• Conducting _________
• Stiffening substance __________
• Waxy ___________
• Pores called ____________
protista *Algae—plant-like _________ organisms
mosses ferns conifersFlowering
plants
_______________
_____________
______
________
Reproduction on land “key”• Needed to have new method to
transport sperm to eggs
• Accomplished by having sex cells carried by _____…or ____…or ________
• And, _______ of developing embryos from __________...
Evolutionary process…con’t
• First, ________
• Followed by _______…
• Then, in the most advanced plants, ________________
ALTERNATING GENERATIONSGametophyte = (n) produces gametesSporophyte = (2n) production of spores by meiosis
Think 4 Major Divisions
Bryophyta Pteridophyta Coniferophyta
Anthrophyta
Division: BryophytesLIVERWORTS & MOSSES
• ~16,000 species• _____ true roots, leaves & stems• root equivalent -- RHIZOIDS• ____________ plants• rely on diffusion or poorly developed
conducting tissues to distribute water & nutrients
NO
N-v
ascu
lar p
lant
s
LIVERWORTS & MOSSES…con’t
• most are _______ (2cm) max height
• main adaptation to land:_____________
REPRODUCTIVE STRUCTURESarchegonia (egg develops)antheridia (sperm formed)
LIVERWORTS & MOSSES…con’t
• sperm must swim to egg through a ____ ___________
• egg emits a _______________ to aid in location by the sperm
• timing of reproduction MUST coincide with _________________…this is very __________ in dry environments
VASCULAR PLANTS (3 MAJOR CATEGORIES)
• Seedless: Club mosses,horsetails, & ferns
• Seed-bearing: Conifers (pines)flowering
plants
vasc
ular
pla
nts
Vascular, ___________ bearing plantsFERNS & CLUB MOSSES
• PTERIDOPHYTA—fernsmost successful
(~12,000 species)• LYCOPHYTA--club mosses
(ground pine)(~1,000 species)
• SPENOPHYTA--horsetails(~15 species)
FERNS & CLUB MOSSES…con’t
• Distribution and dominance-wise, these plant divisions _____ seen better days…
• Life cycles, again, tied to moist conditions…ex: dominant plant body for ferns
is the sporophyte (frond)
Non-flowering, seed bearing plants Plants PINES, GINKGOS, & CYCADS
• Pines (~500 species) (Conifers)
• Ginkgos (1 species: Ginkgo biloba… can you remember this one?)
-- male & female trees-- extinct in wild-- resistant to air pollution
• Cycads (~160 species)
Conifers = EVERGREENS(Division: Coniferophyta)
• Gymnosperm = “____________” in Latin• Pines, spruces, firs, hemlocks, & cypresses• Once more ______________ and dominant on
land• Most are extremely well-adapted to _____(cold),
____ conditions….
Conifers…con’t
• Dry & cold environment adaptations:a) thin needles with ______ cuticle
b) _____ contains “antifreeze”(what gives it a “piney” fragrance)
• How do these adaptations help????
Conifers…reproductive cycle• Dominant form: _____ = diploid sporophyte
• Male & female cones• Pollen (from male cones) dispersed by wind• Pollen landing on scale of female cone
produces pollen tube that burrows into female gametophyte
Flowering Seed Plants ANGIOSPERMS
• Division: ANTHROPHYTA (“anthro” is Greek for “_______”)
• “Angiosperm” is Greek for “________ ___________________” ….angiosperms produce their seeds enclosed within a fruit
• Diverse group….corn, oaks, water lilies, cacti, and buttercups
Angiosperms…con’t• ~230,000 species• “the” ________ plant division for over 100
million years
• 3 major adaptations:a) flowers
b) fruits
c) broad leaves
1
2
3
Flowers• Produced by sporophyte • Males & females generally in same
flower• _______ formed in anther (male)• _______ formed in ovary (female)• Fertilization accomplished with pollen
tube through the stigma
1
All in!
Fruit
• Contains the ovary which contains a ______________
• This adaptation greatly enhanced __________.most seeds pass through digestive tracts of animals unharmed. Some attached to fur.
2
Seeds
• Important source of food for humans….including prehistoric times
a) easy storage (if kept dry)b) source of protein, oils,
carbohydrates, & vitamins…same goes for germinating seed
Broad Leaves
• During favorable conditions…particularly in tropical and temperate zones…_____ ______________ available to collect sunlight for photosynthesis.
• Excess production allows for storage…and subsequent dormant period
3
Broad Leaves…liabilities
• Broad, ________ leaves are more appealing to herbivores than conifer leaves (needles)
• To __________….some have developed defenses: a) thorns, spines, & resins b) chemical compounds that may be toxic or distasteful
protista *Algae—plant-like single-cell organisms
mosses ferns conifersFlowering
plants
All multicelluar
Vascular tissue
Seeds
Flowers
Top Related