GYMNOSPERMS - NAKED SEEDED 

        EVOLUTIONARY DEVELOPMENT OF PLANTS

   1. NO VASCULAR TISSUE - BRYOPHYTES

   2. VASCULAR TISSUE, NO SEEDS - SEEDLESS, VASCULAR PLANTS

   3. SEEDS - NO FLOWERS OR FRUITS - GYMNOSPERMS

   4. FLOWERS AND FRUITS - ANGIOSPERMS

WHY ARE SEEDS AN IMPROVEMENT?

1. FREE-LIVING GAMETOPHYTE IS VULNERABLE
       a. MAY START TO DEVELOPE AT THE WRONG TIME.
       b. FEMALE GAMETOPHYTE AND MALE GAMETOPHYTE MAY NOT BE IN
      THE SAME AREA
       c. WATER MAY BE SCARCE

2. SEEDS ARE MORE TOLERANT TO ENVIRONMENTAL EXTREMES
       a. HEAT
       b. COLD
       c. DROUGHT

3. SEEDS CAN POSTPONE DEVELOPMENT UNTIL CONDI- TIONS ARE
   RIGHT

CHARACTERISTICS

1. SEEDS NOT ENCLOSED IN AN OVARY
2. SEEDS GROWN ON THE SURFACE OFF A MODIFIED LEAF
   (SPOROPHYLL)
3. MODIFIED LEAVES ARE ARRANGED IN A STROBOLI CALLED A CONE
4. HAVE ALTERNATION OF GENERATIONS
5. HETEROSPOROUS
       a. MICROSPORES SHED AS POLLEN
       b. MEGASPORE GERMINATES IN THE STROBOLIS TO PRODUCE THE
      FEMALE GAMETOPHYTE

THE 4 LIVING DIVISIONS OF GYMNOSPERMS

1. GINKGOPHYTA - GINKGO BILOBA

2. CYCADOPHYTA - CYCADS

3. CONIFEROPHYTA (PINOPHYTA)- CONIFERS

4. GNETOPHYTA

DIVISION GINKGOPHYTA

CHARACTERISTICS

1. NOTCHED LEAF   
   http://www.life.umd.edu/pbio100/plso31.jpg
2. DIOECIOUS (TWO “HOUSES” -
SEPARATE SEXES)
3. SPERM FLAGGELATED BUT...
4. FEMALE TREES STINK - SEED INTEGUMENT EMIT A FOUL ODOR
5. GROW WELL IN POLLUTED ENVIRONMENTS
6. NONE FOUND IN NATURE

DIVISION CYCADOPHYTA

10 GENERA AND 100 SPECIES; 2 NATIVE TO THE U.S. - BOTH ZAMIA
SPECIES

1. HAVE PALMLIKE LEAVES - PRODUCE ONE CROWN OF LEAVES A
   YEAR
2. HAVE SPOROPHYLLS (MICROSPOROPHYLLS) THAT ARE ARRANGED
   INTO STROBOLI
3. FEMALE (MEGASPORESPHYLLS)HAVE
MEGASPORES ON SMALL LEAF
   MARGINS

DIOECIOUS

DIVISION GNETOPHYTA

3 GENERA

     EPHEDRA - 40 SPECIES
  GNETUM - 30 SPECIES
  WELWITSCHIA - 1 SPECIES

EPHEDRA

1. MONOECIOUS OR DIOECIOUS
2. COMMON NAME OF MORMON TEA
3. LEAVES SMALL AND NONPHOTOSYNTHETIC AT MATURITY
4. STEMS PHOTOSYNTHETIC

GNETUM

1. DIOECIOUS
2. CLIMBING VINES OR TREES
3. LEAVES BROAD AND SIMPLE

WELWITSCHIA

1. FOUND IN THE NAMIB AND MOSSAMEDES DESERTS OF
   SOUTHWESTERN AFRICA
2. GETS MOST OF IT’S MOISTURE FROM THE FOG
3. STEM UP TO 1.5 METERS IN
DIAMETER
4. HAS A LARGE TAP ROOT
5. HAVE A PAIR OF LARGE STRAP -
SHAPED LEAVES
   a. LEAVES HAVE AN INTERCALARY MERISTEM
      AN INTERCALARY MERISTEM
IS AT THE BASE OF THE
      LEAF
6. PLANTS DIOECOUS
   a. WEIRD SEX
      TUBE GROWS OUT FROM THE EGG TOWARD THE POLLEN
      TUBE

 
     TUBES UNITE

 
     FERTILIZATIOIN OCCURS WITHIN THE UNITED TUBES

 DOUBLE FERTILIZATION OCCURS IN THE GNETOPHYTES

    
FIRST SPERM UNITES WITH THE EGG
     SECOND SPERM UNITES WITH A
FEMALE GAMETOPHYTE CELL AND
     THE RESULTING CELL DISINTGRATES

 
ECONOMIC IMPORTANCE OF GYMNOSPERMS

1. USED FOR MAKING PAPER AND LUMBER
   a. CONIFERS USED FOR 75% OF ALL LUMBER AND FOR PULP
      FOR PAPER
   b. WHITE SPRUCE IS THE CONIFER
USED FOR MAKING PAPER
      PULP
   c. DOUGLAS FIR THE MOST DESIRED TIMBER TREE BECAUSE,
      1. HAS FEW KNOT HOLES
      2. STRONG
      3. USED IN PLYWOOD
   d. REDWOODS PRIZED FOR;
      1. WOOD
        a. LIGHTWEIGHT
        b. STRONG
        c. SOFT
        d. SPLITS EASILY
        e. HAS RESINS THAT INHIBIT GROWTH OF BACTERIA
           AND FUNGI
      2. USED TO MAKE;
        a. PATIO FURNITURE
        b. FENCE POSTS
        c. GREENHOUSE BENCHES

2. USED IN MAKING MUSICAL INSTRUMENTS
   a. SPRUCE - USED AS SOUNDBOARDS IN VIOLINS
3. NONWOOD PRODUCTS USED:
   a. RESIN
      1. MADE UP OF ROSIN AND TURPENTINE

   
     TURPENTINE = LIQUID SOLVENT
USED FOR, OR AS, A,
         a. PAINT AND VARNISH SOLVENT
         b. COMPONENT IN,
            1. DEODERANT
            2. SHAVING LOTION
            3. DRUGS
            4. LIMONINE

         ROSIN USED TO,
         a. IMPROVE GRIP OF,
            1. BULLRIDERS
            2. BASEBALL PITCHERS
            3. GYMNASTS
              4. BALLERINAS (ON TOES OF TOESHOES)

        RESINS USED TO WATERPROOF ROPES, WOOD, SAILS, MUMMY
        WRAPPINGS, WINE CASKS.

        SOURCE OF AMBER

 

ORIGIN OF GYMNOSPERMS

ANCESTORS IN THE DIVISION PROGYMNOSPERMOPHYTA

    
TOTALLY EXTINCT DIVISIONS ARE;

    
1. PTERIDOSPERMOPOHYTA - SEED FERNS
     2. CYCADEOIDOPHYTA - CYCADEOIDS