Lecture Note
Plant Reproduction
Alternation of Generations [has asexual and sexual parts] gametophyte [1n]  produces gametes [1n]
 gametes fuse (fertilization) to form sporophyte [2n]
 sporophyte produces spores [1n] through meiosis
 spores form gametophyte plant
Vegetative Reproduction: reproduction from existing plant structures
[asexual reproduction]
Ferns – non seeded vascular plants
On leaf, flagellated sperm [reprod. cells] need water to swim to eggs [reprod. cells] @ the top of the structure.
Gametophyte is very small [at most, 1cm!]
Sporophyte plant is formed by sperm and egg fertilization.
Flowers – reproductive structure.
petal: leaf-like structure, typically colorful around top of stem; functions to attract insects/animals for pollination
sepal: leaf-like, usually green, encircles bottom of flower
stamen: male reproductive organ o filament: long tube-like projection that holds anther o anther: contains pollen [sperm]
pistil: female reproductive organ o ovary [contains ovules/eggs], style [long part connecting ovary & stigma], stigma [sticky top portion @ top of style]

Why Flowers? Used to attract pollinators for fertilization [like, the sexy-clothes of the plant]. They do this through colors [UV colors, too], patterns, or shapes.
Fertilization – this happens MANY times to complete fertilization – think of how many seeds are in a watermelon!
Ovule = plant egg [female gamete]; Pollen = plant sperm [male gamete]
Think about all the pollen on your car, home, etc. in the spring/summer in Georgia!!
Steps of fertilization:
1.
pollen lands on stigma [carried by wind, insect…etc]
2.
pollen tube pollen tube grows down the style to the ovules for fertilization
Seeds – zygote of the plant
after fertilization, flower parts die
the ovary wall becomes the fruit and the ovules become seeds

Seed dispersal – burrs, maple “helicopters,” dandelion “poofs,” some need to be eaten…
greater dispersal = hopefully less competition where they land for resources
where seeds end up is due to chance
Germination: the beginning of development of the embryo into a new plant.
remember dormancy – many seeds can remain dormant for long periods of time!]
requires water, oxygen, correct temperature o before germination can occur, some require:
 freezing [apples]
 fire [conifers]
 saturation of salt water [coconuts]
 or other conditions
once germination begins, it cannot be halted except for death.
Vegetative Reproduction: o Bulbs, rhizomes, tubers – faster than sexual reproduction
Flowers: o Complete flowers: contain both reproductive sex parts
[lilies] o Incomplete flowers: contain only one sex or another [corn]