1. Plant Reproduction

2. Structure of a Flower 1. Pistil 2. Stigma 3. Style 4. Ovary 5. Stamen
6. Filament
7. Anther
8. Petal
9. Sepal
10. Receptacle
11. Stem

3. Male Reproductive Structure
The stamen consists of two parts: Anther and Filament
The anther is where meiosis occurs to produce haploid pollen
The filament is a stalk that supports the anther

4. Female Reproductive Structure
The pistil consists of the stigma, style and ovary
The sticky stigma receives the pollen from the anther
The pollen grows a tube down through the style
Meiosis occurs in the ovary to produce haploid ovules

5. Accessory Structures
The calyx consists of all the sepals, which protects the flower before it opens
The corolla consists of all the petals, which serve to attract pollinators through color and scent

6. Pollination
Wind, insects or other animals transfer pollen from the anther of one flower to the stigma of another
Flowers vary depending on pollination mechanism

7. Pollination Animation

8. Pollination Vectors Wind Pollination: Dull, scentless
flowers with reduced petals
Bees/Butterfly Pollination: Bright
color, nectaries, scent.
They sip nectar, get pollen on coats,
transfer pollen from flower to flower

9. Bird Pollination: Nectaries, bright
colors, tube-like flowers
Moth Pollination: White petals,
open at night
Fly Pollination:Rank odor, flesh
colored petals

10. Fertilization
After pollen lands on stigma, a pollen tube grows down through the style to ovary
Tube contains two sperm nuclei
In ovary, there is one egg or ovule nucleus and two polar nuclei
Double fertilization occurs: one sperm nucleus fertilizes the egg, the other the two polar nuclei

11. Result of Double Fertilization
The sperm nucleus and egg nucleus join to form a 2n (diploid) embryo
The other sperm nucleus and the two polar nuclei join to form a 3n (triploid) endosperm. The endosperm is the food supply for the embryo.

12. Seed and Fruit Development
After fertilization, the petals and sepals fall off flower
Ovary “ripens” into a fruit
The ovule develops into a seed

13. Seed Dispersal Mechanisms- Allow plants to colonize new areas and avoid shade of parent plant
Wind Dispersal - Flight mechanisms,
like parachutes, wings, etc.
Ex. Dandelion, maples, birch
Animal Dispersal - Fleshy fruits which
animals eat, drop undigested seeds in
feces or burrs which stick to
animals’ coats

14. Gravity Dispersal - Heavy nuts fall to ground and roll
ex. acorns
Water Dispersal - Plants
near water create floating
fruits
ex. coconuts

15. Monocot Seed Germination
Monocots grow straight up with coleoptile sheath covering shoot
One embryonic leaf
Seed remains underground

16. Dicot Seed Germination
Curved stem comes up out of soil
Two embryonic leaves
Seed goes above soil

17. Parts of the Embryo Epicotyl - Grows into the leaves of the plant
Hypocotyl - Becomes the stem
Radicle - Becomes the root