Plant Reproduction

1
Plant Reproduction
In a nutshell
2
Plant Diversity
mosses
ferns
conifers
flowering plants
Bryophytesnon-vascularland plants
Pteridophytesseedless vascular plants
Gymnospermpollen naked seeds
Angiospermflowers fruit
flowers fruits
pollen seeds
vascular system
xylem cellstracheids
common ancestor
3
Animal vs. Plant life cycle
Animal
Plant
diploidmulticellularindividual 2n
diploidmulticellular sporophyte 2n
mitosis
meiosis
meiosis
mitosis
fertilization
spores 1n
gametes 1n
fertilization
mitosis
mitosis
haploidmulticellular gametophyte 1n
haploidunicellular gametes 1n
alternation of generations
4
Bryophytes

• Mosses liverworts
• non-vascular
• swimming sperm
• dominant haploid gametophyte
• dependent sporophyte
• spores for reproduction

diploidmulticellular sporophyte 2n
mitosis
meiosis
fertilization
spores 1n
gametes 1n
mitosis
mitosis
haploidmulticellular gametophyte 1n
alternation of generations
5
Pteridophytes

• Ferns
• vascular
• swimming sperm
• dominant sporophyte
• independent gametophyte
• fragile
• spores for reproduction

diploidmulticellular sporophyte 2n
mitosis
meiosis
fertilization
spores 1n
gametes 1n
mitosis
mitosis
archegonia
haploidmulticellular gametophyte 1n
antheridia
alternation of generations
6
Gymnosperm

• Conifers
• vascular
• pollen (sperm)
• dominant sporophyte
• dependent reduced gametophyte
• cones, seeds for reproduction

diploidmulticellular sporophyte 2n
mitosis
meiosis
fertilization
spores 1n
gametes 1n
mitosis
mitosis
haploidmulticellular gametophyte 1n
female
male
7
Angiosperm

• Flowering plants
• vascular
• pollen (sperm)
• dominant sporophyte
• dependent reduced gametophyte
• flowers, fruits, seeds for reproduction

diploidmulticellular sporophyte 2n
mitosis
meiosis
fertilization
spores 1n
gametes 1n
mitosis
mitosis
haploidmulticellular gametophyte 1n
8
Angiosperm flowering plants
9
Angiosperm life cycle
pollengrains
malegametophytein pollen(haploid)
fertilization
femalegametophytein ovary(haploid)
sporophytein seed (diploid)
10
Flower

• Modified shoot with 4 ringsof modified leaves
• sepals
• petals
• stamens
• male
• pollen
• carpel
• female
• egg

11
Double Fertilization
Whats theadaptiveadvantage?
pollen grain
sperm cells
pollen tube
pollination
ovule

• Endosperm (3n)
• food in seed
• grains
• beans
• coconut milk

ovary
endosperm (3n)
pollen tube
polarnuclei
zygote (2n)
egg cell
12
Seed Plant embryo
seed coat

• Seed offers
• protection for embryo
• stored nutrients for growth of embryo

endosperm3n
cotyledons
embryo
cotyledons seed leaves, first leaves of new
plant
13
Identify the flower structures
14
Flower variations
15
Corn reproduction
seeds
flowers seeds
tassel
pollen
silk?stigma style
female?carpel
male?stamens
16
Co-evolution flowers pollinators
How a bee sees a flowerinsects see UV light a
bulls-eye to the nectar
17
Angiosperm fruiting plants
18
Other fruits
19
Fruit development

• Peach, plum, apricot, cherry
• 1 flower 1 carpel 1 ovary 1 seed

20
Fruit development

• Apple, pear
• 1 flower 5 carpels many ovaries many seeds

21
Fruit development

• Citrus fruit
• 1 flower many carpels many ovaries many
  seeds

22
Fruit development

• Raspberry, strawberry
• 1 flower many ovaries many seeds

23
Seed dispersal

• Plants produce enormous numbers of seeds to
  compensate for low survival rate
• vast amount of genetic variation for natural
  selection to screen

r-strategy
K-strategy
24
Any Questions??