Lecture 3 – Pollination and double fertilization

Vocabulary flashcards covering pollination concepts including biotic/abiotic pollination, pollinator types, plant strategies, and the basics of double fertilization.

Pollination

Transfer of pollen from anther to stigma, enabling fertilization.

Abiotic pollination

Pollination by non-living agents (wind or water); flowers are usually small, colorless, nectarless, and odorless.

Biotic pollination

Pollination by living animals (insects, birds, bats, etc.).

Generalist pollinators

Pollinators that visit many plant species rather than specializing on one.

Specialist pollinators

Pollinators that interact with a narrow set of plant species, often showing tight coevolution.

Nectar

Carbohydrate-rich reward that attracts pollinators and provides energy.

Pollen

Male gametophyte; protein-rich powder that carries sperm and may be colorized.

Plant trickery (mimicry/deception)

Plants invest in mimicry to resemble insects or mates to lure pollinators.

Beetle pollination – tulip tree

Tulip tree flowers with musty odors to attract beetle pollinators.

Amorphophallus titanium

Plant that emits heat and foul odor to attract beetles; may trap insects to ensure pollen transfer.

Corpse flower

Smells like rotting meat to attract flies and beetles for pollination.

Flower color function

Petal colors provide landing cues for pollinators; some colors are seen in UV by insects.

Bird pollination coevolution

Flower shape and nectar evolve with bird beaks; example involves coevolved relationships like sicklebills.

Bat pollination

Night-blooming flowers; dull petal colors and strong musty odors attract bats.

Star orchid

Orchid with an extremely long pollen tube; Darwin predicted a long-tongued pollinator.

Xanthopan morganii praedicta

Hawk moth predicted by Darwin to pollinate the star orchid; later observed.

Wind/pollination pollen traits

Abiotic wind pollination uses small, aerodynamic pollen and colorless flowers with lots of pollen.

Stigmatic surfaces

Enlarged stigmas that effectively catch wind-transported pollen.

Sporopollenin

Hard, decay-resistant polymer in pollen walls; aids fossilization.

Angiosperms

Flowering plants; seeds enclosed in ovaries; meiosis produces megaspores and microspores; anthers are four-lobed.

Megaspore

Female spore that gives rise to the female gametophyte.

Microspore

Male spore that develops into pollen grain (male gametophyte).

Anthers

Flower structure with four lobes that produce microspores/pollen.

Double fertilization

Two sperm from the pollen grain fertilize two targets: one with the egg (embryo) and one with the central cell’s polar nuclei (endosperm).

Endosperm

Triploid tissue that nourishes the developing embryo.