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Unformatted text preview: Wind pollinated plants:
• Most gymnosperms (non-flowering seed plants)
• Only 10% (25,000) of the angiosperm species are wind-pollinated.
• Includes all the cereal plants such as wheat, rice and maize.
• Also includes most of the trees found in forests.
• Must produce huge quantities of pollen to increase chance of pollination.
• 1 anther on a maize flower produces 3000 pollen grains
(total = 18 million pollen grains per plant!)
• Flowers are usually small and inconspicuous,
do not produce nectar or have any scent
(since don’t need to attract animal pollinators).
2. Animal pollinated plants: 19 Wind pollinated plants liberate gigantic quantities of pollen allergic rhinitis Pollination 20 2. Animal pollinated plants: Insects Birds Bats 21 Insect pollinated plants:
(many angiosperms, few gymnosperms)
• Insects are ATTRACTED
to flowers by advertising colors
and or smells
• Insects are REWARDED
• Either they eat some of the
pollen and/or nectar
to make it worth their while • Pollen grains stick to insect
on male flower and are
transferred to female flower –
this is “pollination” Insect pollination is a form of INSECT – PLANT MUTUALISM 23 Bird pollinated plants: (some angiosperms only) Hummingbird pollinated flowers:
Lots of nectar – hidden down long structure – deters nectar thieves 24 Bat pollinated flowers (some angiosperms only)
Organ-pipe cactus flower
and long-nosed bat 26 Pollination vs. Fertilization Pollination:
in pollen grain,
to ♀ gametophyte,
in the ovule
sperm & egg
ovule May occur years
after pollination! Angiosperm
life cycle 27 Spore vs. Seed
Spores Description Seeds A haploid cell
made in the sporangium
of the sporophyte via meiosis A sporophyte embryo (2n)
+ nutrients (n) (remnants of
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