REPRODUCTION IN SEED
PLANTS – CH.24
COMPLETE (PERFECT)
FLOWERS
•
•
1.
2.
3.
4.
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
Section 24-1
The Structure of a
Flower
Stamen
Anther
Filament
Ovule
Stigma
Style
Carpel
Ovary
Petal
Sepal
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 FLOWERSMALE & FEMALE FLOWERS ON TWO
DIFFERENT PLANTS (EG. DATES, PLUMS,
ASH, MAPLES, SPINACH)
NONESSENTIAL FLOWER PARTS
(NOT INVOLVED IN
REPRODUCTION)
• SEPALS – OUTERMOST WHORL OF LEAFLIKE 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)
REPRODUCTIVE PARTS – MALE
(ESSENTIAL PARTS)
Stamen
Anther
Filament
Ovule
Stigma
Style
Carpel
Ovary
Petal
Sepal
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. FILAMENT:STALK-LIKE
PART THAT SUPPORTS THE
ANTHER
REPRODUCTIVE PARTS –
FEMALE (ESSENTIAL PARTS)
PISTIL – FEMALE REPRODUCTIVE ORGAN (ALSO CALLED
CARPEL) MADE OF:
1.
STIGMA: STICKY PART AT TOP – MAY HAVE ONE
TO SEVERAL DISTINCT LOBES – CONTAINS
MOISTURE & SUGARS NEEDED FOR POLLEN
GRAIN GERMINATION AFTER POLLINATION
2.
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.
3.
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/EGG. 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
Stamen
Anther
Filament
Ovule
Stigma
Style
Carpel
Ovary
Petal
Sepal
FLOWER CLASSIFICATION
• MONOCOTS –
FLOWER PARTS IN
3’S OR MULTIPLES
OF 3 (LILY)
• DICOTS – FLOWER
PARTS IN 4’S OR
5’S OR MULTIPLES
OF 4 OR 5
(BUTTERCUPS OR
ROSES)
ANGIOSPERM LIFE CYCLE
Video
Life Cycle of Angiosperms
• Click the image to play the video
segment.
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!!!
GERMINATING LILY POLLEN
GRAIN
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
EMBRYO SAC
POLLINATION TO
SPOROPHYTE
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)
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
DOUBLE FERTILIZATION
(CHARACTERISIC OF
ANGIOSPERMS)
1. SPERM + EGG = EMBRYO(2n)
2. SPERM + 2 POLAR NUCLEI
CELLS = ENDOSPERM (3n)
SEED/FRUIT FORMATION
• OVULE WALL
HARDENS TO FORM
SEED COAT –
SURROUND/PROTECT
EMBRYO &
ENDOSPERM
• OVARY WALL GETS
THICKER TO FORM
FRUIT WHICH
ENCLOSES SEEDS
SEEDS IN A POD
SEEDS
3 PARTS
1. EMBRYO – YOUNG
PLANT
2. ENDOSPERM –
STORED FOOD
3. SEED COAT PROTECTION
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
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)
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:
1.
MITOSIS- “COPIES” OF PARENT CELL
2.
SPORES – CELL ENCLOSED IN
PROTECTIVE WALL, UNDER FAVORABLE
CONDITIONS WILL RUPTURE, GROW,
FORM NEW ORGANISM
3.
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
4.
BUDDING – OUTGROWTH ON PARENT
BREAKS OFF & FORMS WHOLE NEW
ORGANISM
(EG. SPONGE, HYDRA, YEAST)
5.
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):
1. SPONGES
2. COELENTERATA
3. PLATYHELMINTHES
4. ALL OTHER HIGHER ANIMALS
5. SOME TYPES OF ALGAE (RED, BROWN,
GREEN)