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 GENERATIONS Gametophyte = (n) produces gametes Sporophyte = (2n) production of spores by meiosis
Division: Bryophytes LIVERWORTS & MOSSES ~16,000 species _____ true roots, leaves & stems root equivalent -- RHIZOIDS ____________ plants rely on diffusion or poorly developed conducting tissues to distribute water & nutrients NON-vascular plants
LIVERWORTS & MOSSES…con’t most are _______ (2cm) max height main adaptation to land: _____________ REPRODUCTIVE STRUCTURES archegonia (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
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
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