1. Reproduction In Plants

2. Pollination Nation: Plant Sex
Pollination the mixing of male gametes (pollen grains) with female gametes (ovule) to reproduce sexually
Two Styles of Pollination:
Insect-pollination plant grows flowers and releases scents to attract pollinators (insects/birds)
Symbiosis both groups gain something
Flower has pollen mixed with ovule of different plants
Insect gets nectar (glucose energy drink)
Wind-pollination plant is designed for pollen to be carried by the wind
No energy wasted on nectar/scents
Pollination success rate is lower

3. Structure of a Flower (Insect)
Petals display bright colors, patterns, and scents to attract pollinators
Stamen male organ made of a filament holding up an anther (produces pollen grain)
Sepal protective layer around carpel
Carpel female sex organ made of the…
Stigma entrance where pollen grains must land
Style narrow tube leading to ovary
Ovary container for ovules (eggs)
Ovule female gametes kept inside two different ovaries; 6 ovules per ovary
Nectary produced nectar for insect
Stigma
Carpel
Stamen
Anther
Style
Filament
Ovary
Nectary
Petal
Sepal
Ovule

4. Structure of a Flower (Wind)
Inflorescence groups of spikelets on a branch
Spikelet group of flowers
Stamen male organ made of filaments and anthers; millions are pollen grain are produced, but most are wasted
Feathery Stigma long filament with net-like fibers designed for catching pollen grains in the air
Style tube leading to plant ovary
Ovary contains the female gametes (ovules)
Inflorescence
Spikelet
Anther
Filament
Filament
Stigma
Style
Ovary

5. Insect vs. Wind Petals Nectaries Stamens Pollen Carpels
Compare the structural differences between the two pollination styles:
Structure
Insect-Pollination
Wind-Pollination
Petals
Nectaries
Stamens
Pollen
Carpels
Absent; no need for them
Present; colorful and scented
Present; rewards for insect
Absent; no need for them
Attached to short filaments inside the flower
Attached to long filaments and hang outside the flower
Small quantities and sticky; attach to insects easily
Large quantities, smooth, and very light so to be carried by the wind
Sticky, small stigmas inside the flower
Large and feathery for catching pollen; extend outside flower

6. Self and Cross Pollination
Depending on environmental factors, flowering plants can be pollinated by another plant or by themselves
Cross-Pollination mixing of gametes from two different plants of the same species
Produces more variation in offspring’s DNA
Requires pollen from genetically different partner, that might not be available
Most plants hope for this style
Self-Pollination Plan B; plant mixes is own gametes together to become fertilized
Because of Meiosis, some variation is made
If plant is not pollinated by a certain point, the plant will self-pollinate so the gametes are not wasted