Stigma Anther Carpel Style Filament Ovary Petal …...(a) A schematic diagram of the ABC hypothesis...
Transcript of Stigma Anther Carpel Style Filament Ovary Petal …...(a) A schematic diagram of the ABC hypothesis...
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Stamen
Petal
Filament
Anther Carpel Stigma
Ovary
Style
Ovule
Sepal
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(b) Side view of flowers with organ identity mutations
(a) A schematic diagram of the ABC hypothesis
Wild type Mutant lacking A
Stamen Carpel
Petal
Sepal Mutant lacking B Mutant lacking C
Stamens Carpels
Petals Sepals
Stamen
Carpel
Petal
Sepal
A B
C
C gene activity B + C
gene activity
A + B gene
activity
A gene activity
Active genes: Whorls:
A B
C B B B
A A A C C C A B B B B A A A
A A C B
C B B B
C C C C C C A C A A A C C C A A
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Discharged sperm nuclei (n)
Carpel Anther
Ovary
Seed
Germinating seed
Seed coat (2n) Endosperm (3n)
Embryo (2n)
Mature flower on sporophyte plant (2n)
Female gametophyte (embryo sac)
Nucleus of developing endosperm (3n)
Zygote (2n) Egg nucleus (n)
Egg (n)
Antipodal cells
Synergids
Polar nuclei in central cell
Haploid (n) Diploid (2n)
Key
MEIOSIS
FERTILIZATION
Sperm (n)
Pollen tube
Integuments
Surviving megaspore (n)
Megasporangium (2n)
Style
Pollen grains
Sperm
Stigma Pollen tube
Tube nucleus
Tube cell Generative cell Ovule with
megasporangium (2n) Male
gametophyte (in pollen grain) (n)
MEIOSIS Microspore (n)
Microsporocytes (2n) Microsporangium
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Abiotic pollination by wind Pollination by insects
Common dandelion under ultraviolet light
Common dandelion under normal light
Hazel staminate flower (stamens only)
Hazel carpellate flower (carpels only)
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Pollination by bats or birds
Long-nosed bat feeding on cactus flower at night
Hummingbird drinking nectar of columbine flower
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Zygote (2n) (egg plus sperm)
Endosperm nucleus (3n) (two polar nuclei plus sperm)
Polar nuclei
Polar nuclei
Pollen grain
Ovule
Egg
Synergid
Two sperm Ovule
Two sperm
Egg
Stigma Pollen tube
Style Ovary
Micropyle
Tube nucleus
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Ovule
Integuments
Zygote
Terminal cell
Suspensor
Seed coat
Proembryo
Endosperm nucleus
Zygote
Basal cell
Basal cell
Endosperm Suspensor
Root apex Shoot apex Cotyledons
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Seed coat
Endosperm
Radicle Hypocotyl
Epicotyl
Cotyledons
Seed coat
Radicle Hypocotyl Epicotyl
Cotyledons
Pericarp fused with seed coat
Radicle Hypocotyl Epicotyl
Scutellum (cotyledon)
Endosperm Coleoptile
Coleorhiza
(c) Maize, a monocot
(a) Common garden bean, a eudicot with thick cotyledons
(b) Castor bean, a eudicot with thin cotyledons
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Radicle
Hypocotyl Epicotyl
Cotyledon
Foliage leaves
Coleoptile
Seed coat
(b) Maize
Cotyledon
Hypocotyl Cotyledon
Hypocotyl
Foliage leaves
Coleoptile
Radicle
(a) Common garden bean
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(b) Aggregate fruit
Stamen
(a) Simple fruit (c) Multiple fruit (d) Accessory fruit
Stamen
Stamen
Ovary
Stigma
Stigma
Stigma
Ovary
Stamen
Ovary (in receptacle)
Ovule Ovule
Seed
Pea flower
Pea fruit
Raspberry flower
Carpels
Pineapple inflorescence
Raspberry fruit
Carpel (fruitlet)
Pineapple fruit Apple fruit
Each segment develops from the carpel of one flower
Flower Style Petal
Sepal
Apple flower
Sepals
Seed
Remains of stamens and styles
Receptacle
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Dispersal by water
Coconut seed embryo, endosperm, and endocarp inside buoyant husk
Giant seed of the tropical Asian climbing gourd Alsomitra macrocarpa
Dispersal by wind
Dandelion “seeds” (actually one-seeded fruits) Dandelion fruit
Tumbleweed Winged fruit of a maple 12
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Dispersal by animals
Fruit of puncture vine (Tribulus terrestris)
Seeds dispersed in black bear feces
Squirrel hoarding seeds or fruits underground
Ant carrying seed with attached “food body”
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(a) Staminate flowers (left) and carpellate flowers (right) of a dioecious species
(b) Thrum and pin flowers Thrum flower Pin flower
Stamens Stamens Styles
Styles
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Asexual reproduction in aspen trees 15 © 2014 Pearson Education, Inc.
Developing root Laboratory cloning of a garlic plant
(c) (a) (b)
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