REPRODUCTION IN SEED PLANTS

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REPRODUCTION IN SEED PLANTS CH.24
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COMPLETE (PERFECT) FLOWERS

• COMPLETE FLOWERS HAVE 4 TYPICAL FLOWER PARTS
  STAMENS, PISTILS, SEPALS, AND PETALS.
• THE BASIC STRUCTURE OF A TYPICAL FLOWER IS MADE
  UP OF FOUR CONCENTRIC WHORLS (CIRCLES) IN ORDER
  FROM OUTER PART TO INNER PART
• CALYX OUTERMOST WHORL MADE UP OF ALL OF THE
  SEPALS
• COROLLA NEXT WHORL MADE UP OF ALL OF THE
  PETALS
• ANDROECIUM NEXT WHORL MADE UP OF ALL OF THE
  STAMENS
• GYNOECIUM INNERMOST WHORL MADE UP OF ONE OR
  MORE PISTILS

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 The Structure of a Flower
Section 24-1
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ESSENTIAL FLOWER PARTS (REQUIRED FOR REPRODUCTION)

• PERFECT FLOWERS BOTH KINDS OF REPRO PARTS
  (BISEXUAL) MAY HAVE SELF OR CROSS POLLINATION
  MOST FLOWERS (EG. ROSES, GLADIOLUS,
  BUTTERCUPS)
• IMPERFECT FLOWERS ONLY ONE KIND OF REPRO PART
  (UNISEXUAL) CAN ONLY HAVE CROSS POLLINATION
• 1. STAMINATE FLOWERS MALE STAMENS ONLY (MAKE
  POLLEN) TASSEL OF CORN PLANT
• 2. PISTILLATE FLOWERS FEMALE ONLY HAVE
  PISTILS (MAKE EGGS) SILK PART OF CORN PLANT
• MONOECIOUS PLANTS IMPERFECT
• FLOWERS- MALE FEMALE FLOWERS
• ON THE SAME PLANT (EG. CORN, SQUASH,
• CUCUMBER, PUMPKIN, WALNUTS)
• DIOECIOUS PLANTS IMPERFECT FLOWERS-
• MALE FEMALE FLOWERS ON TWO
• DIFFERENT PLANTS (EG. DATES, PLUMS,
• ASH, MAPLES, SPINACH)

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NONESSENTIAL FLOWER PARTS (NOT INVOLVED IN
REPRODUCTION)

• SEPALS OUTERMOST WHORL OF LEAF-LIKE PARTS,
  USUALLY SMALL GREEN. ALL OF THE SEPALS MAKE UP
  THE CALYX
• PETALS NEXT WHORL OF LEAF-LIKE PARTS, USUALLY
  LARGE, COLORFUL, AND FRAGRANT. ALL OF THE PETALS
  ON ONE FLOWER MAKE UP THE COROLLA
• IN SOME FLOWERS THE SEPALS LOOK EXACTLY LIKE
  THE PETALS IN SIZE, SHAPE, COLOR (EG. LILY),
  BUT THE OUTERMOST WHORL (CALYX) IS STILL MADE UP
  OF ALL OF SEPALS
• IN SOME ATYPICAL FLOWERS THE SEPALS AND PETALS
  DO NOT LOOK TYPICAL NOT COLORFUL OR LARGE AT
  ALL (EG. WEEDS LIKE JOHNSON GRASS), BUT THESE TWO
  PARTS STILL MAKE UP THE OUTER 2 WHORLS (CALYX
  COROLLA)

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REPRODUCTIVE PARTS MALE (ESSENTIAL PARTS)

• STAMEN MALE REPRODUCTIVE ORGAN. MADE OF
• 1. ANTHER ENLARGED TIP THAT PRODUCES POLLEN
  EACH POLLEN GRAIN HAS 2 HAPLOID (N) NUCLEI (1 IS
  THE TUBE NUCLEUS, OTHER THE GERM NUCLEUS)
• 2. FILAMENTSTALK-LIKE PART THAT SUPPORTS THE
  ANTHER

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REPRODUCTIVE PARTS FEMALE (ESSENTIAL PARTS)

• PISTIL FEMALE REPRODUCTIVE ORGAN (ALSO CALLED
  CARPEL) MADE OF
• STIGMA STICKY PART AT TOP MAY HAVE ONE TO
  SEVERAL DISTINCT LOBES CONTAINS MOISTURE
  SUGARS NEEDED FOR POLLEN GRAIN GERMINATION AFTER
  POLLINATION
• STYLE STALK-LIKE PART THAT SUPPORTS THE STIGMA-
  POLLEN TUBE WILL GO DOWN STYLE TO OVARY. AT THE
  TOP PART OF THE STYLE, MITOSIS OF GERM NUCLEUS
  WILL FORM 2 SPERM NUCLEI THESE WILL BE CARRIED
  TO THE EGG BY THE POLLEN TUBE. THE POLLEN GRAIN
  AND POLLEN TUBE COMPLETELY ELIMINATE THE NEED FOR
  H20 FOR SWIMMING SPERM THAT LIMITED MOSS FERN
  REPRO.
• OVARY ENLARGED BASE AT BOTTOM OF PISTIL
• OVULE (EMBRYO SAC) FEMALE GAMETOPHYTE WILL
  PRODUCE 8 HAPLOID NUCLEI WHICH POSITION
  THEMSELVES AS ANTIPODALS/POLAR NUCLEI/SYNERGIDS/EG
  G. THE EGG POLAR NUCLEI WILL BE INVOLVED IN
  DOUBLE FERTILIZATION FORMING THE ZYGOTE (EMBRYO)
  THE ENDOSPERM (STORED FOOD) INSIDE THE
  DEVELOPING SEED
• PERICARP OUTER WALL OF OVARY THAT WILL ENLARGE
  WHEN MATURE, FORMING FRUIT
• CARPELS SECTIONS W/IN THE OVARY WHERE
  DEVELOPING SEEDS WILL BE FOUND. THE OF CARPELS
  OFTEN EQUALS THE OF LOBES FOUND MAKING UP THE
  STIGMA

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FLOWER CLASSIFICATION

• MONOCOTS FLOWER PARTS IN 3S OR MULTIPLES OF 3
  (LILY)
• DICOTS FLOWER PARTS IN 4S OR 5S OR MULTIPLES
  OF 4 OR 5 (BUTTERCUPS OR ROSES)

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ANGIOSPERM LIFE CYCLE
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Video
Video
Life Cycle of Angiosperms

• Click the image to play the video segment.

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MICROSPOROGENESIS (IN ANTHER POLLEN FORMATION)

1. MICROSPORE (POLLEN) MOTHER CELL (2n) UNDERGOES 1
   MEIOTIC DIVISION TO PRODUCE 4 MICROSPORES (n)
2. 4 MICROSPORES (n) UNDERGO 1 MITOTIC DIVISION TO
   PRODUCE 4 HAPLOID POLLEN GRAINS WITH 2 NUCLEI
   EACH (GENERATIVE NUCLEUS TUBE NUCLEUS).
3. POLLEN GRAIN (IN ANTHER AWAITING ITS RUPTURE) IS
   THE MALE GAMETOPHYTE!!!

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GERMINATING LILY POLLEN GRAIN
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MEGASPOROGENESIS (IN OVARY) EMBRYO SAC FORMATION

• 1.MEGASPORE MOTHER CELL (2n) UNDERGOES 1 MEIOTIC
  DIVISION TO PRODUCE 1 HAPLOID CELL (OTHER 3
  DISINTEGRATE)
• 2.1 MEGASPORE UNDERGOES 3 MITOTIC DIVISIONS TO
  PRODUCE 1 EMBRYO SAC THAT HAS 7 CELLS IN IT 3
  ANTIPODALS (n), 2 SYNERGIDS (n), 1 EGG CELL (n)
  1 POLAR NUCLEI CELL (2n).
• 3. EMBRYO SAC IS THE FEMALE GAMETOPHYTE!

• BOTH THE POLLEN GRAIN AND THE EMBRYO SAC ARE
• 1. MICROSCOPIC
• 2. INCONSPICUOUS
• 3. SHORT-LIVED
• 4. DEPENDENT

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EMBRYO SAC
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POLLINATION TO SPOROPHYTE
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POLLINATION FOLLOWED BY FERTILIZATION

• 1.POLLEN GRAIN LANDS ON THE STIGMA GERMINATES,
  FORMING A POLLEN TUBE (FROM TUBE NUCLEUS) THAT
  CARRIES SPERM NUCLEI THROUGH THE STYLE INTO THE
  OVARY
• 2. WHILE IN THE POLLEN TUBE, THE SPERM NUCLEUS
  (n) DIVIDES (MITOSIS) TO PRODUCE 2 SPERM NUCLEI
  (n)

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FERTILIZATION

1. TUBE NUCLEUS DISINTEGRATES ONCE POLLEN TUBE
   PUNCTURES THE OVULE (IN OVARY)
2. FERTILIZATION! SPERM (n) EGG(n) EMBRYO (2n)
3. SPERM (n) 2 POLAR NUCLEI CELLS(n) ENDOSPERM
   (3n)
4. SYNERGIDS ANTIPODALS DISINTEGRATE

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DOUBLE FERTILIZATION(CHARACTERISIC OF
ANGIOSPERMS)

• 1. SPERM EGG EMBRYO(2n)
• 2. SPERM 2 POLAR NUCLEI CELLS ENDOSPERM (3n)

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SEED/FRUIT FORMATION

• OVULE WALL HARDENS TO FORM SEED COAT
  SURROUND/PROTECT EMBRYO ENDOSPERM
• OVARY WALL GETS THICKER TO FORM FRUIT WHICH
  ENCLOSES SEEDS

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SEEDS IN A POD
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SEEDS

• 3 PARTS
• EMBRYO YOUNG PLANT
• ENDOSPERM STORED FOOD
• SEED COAT - PROTECTION

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REPRODUCTION IN HIGHER PLANTS

• GYMNOSPERMS (CONIFERS)
• HAVE CONES
• DRY SEEDS ARE EXPOSED ON SCALES OF CONES (NOT
  ENCLOSED)
• EG. PINE, SPRUCE, FIR, CEDAR

• ANGIOSPERMS (FLOWERING PLANTS)
• PRODUCE FRUIT
• SEEDS ENCLOSED (PROTECTED) BY FRUIT
• EG. ROSE, LILY, TULIP, DAISY, SUNFLOWER
• VEGETABLES TOMATOES, BEANS, SQUASH, WATERMELON
• TREES MAGNOLIA, FRUIT
• UNUSUAL FLOWERING PLANTS (ATYPICAL FLOWER PARTS)
• TREES PECAN, OAK
• VEGETABLES CORN
• GRASSES CEREALS, GRAINS, WEEDS

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STEPS IN PLANT REPRODUCTION

1. FORMATION OF EGG POLLEN (SPERM)
2. POLLINATION (TRANSFER)
3. POLLEN TUBE FORMATION (GROWING DOWN STYLE)
4. FERTILIZATION/FUSION (OVARY)
5. FRUIT FORMATION (BASE OF FLOWER)
6. SEED DEVELOPMENT (INSIDE FRUIT)
7. SEED DISPERSAL (SPREADING)
8. SEED GERMINATION (SPROUTING)
9. GROWTH OF PLANT
10. FORMATION OF FLOWER/CONE (MALE FEMALE
    GAMETOPHYTES)

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REPRODUCTION BASIC PROPERTY OF ALL LIFE,
MAINTAINS THE SPECIES 2 METHODS

• ASEXUAL
• OFFSPRING FORMED FROM 1 PARENT NO VARIATION,
  OFFSPRING IDENTICAL TO PARENT-ONLY SOURCE OF
  VARIATION MUTATION
• EXAMPLES
• MITOSIS- COPIES OF PARENT CELL
• SPORES CELL ENCLOSED IN PROTECTIVE WALL, UNDER
  FAVORABLE CONDITIONS WILL RUPTURE, GROW, FORM NEW
  ORGANISM
• VEGETATIVE PROPAGATION- PLANT REPRO WITHOUT SEEDS
  PART OF PARENT CAN FORM OFFSPRING
• LEAVES AFRICAN VIOLETS, CHICKENS HENS,
  BEGONIA
• STEMS ROSES, STRAWBERRIES, BLACKBERRIES, PEARS,
  PEACHES, APPLES, POTATOES
• BUDDING OUTGROWTH ON PARENT BREAKS OFF FORMS
  WHOLE NEW ORGANISM
• (EG. SPONGE, HYDRA, YEAST)
• FRAGMENTATION CELLS BREAK OFF PARENT TO FORM
  NEW ORGANISM
• (EG. BLUE-GREEN ALGAE, SPONGES, COELENTERATES
  (SEA ANEMONE)

• SEXUAL
• UNION OF 2 TYPES OF CELLS (2 SETS OF DNA)
• VARIATIONS OFFSPRING DIFFER FROM PARENTS
• FERTILIZATION UNION OF GAMETES AFTER MEIOSIS
• MEIOSIS HAPLOID GAMETES THAT MAINTAIN SPECIES
  CHROMOSOME - FERTILIZATION RESTORES SPECIES
• EXAMPLES (ALL CAN FORM GAMETES)
• SPONGES
• COELENTERATA
• PLATYHELMINTHES
• ALL OTHER HIGHER ANIMALS
• SOME TYPES OF ALGAE (RED, BROWN, GREEN)