1. Earth’s dominant plants
Angiosperms
Earth’s dominant plants

2. Angiosperm Characteristics
Vascular
Flowering plants
Double fertilization
Seeds are covered in a fruit
Dominant sporophyte generation
Xylem – vessel elements
Phloem – sieve tube elements

3. 2 Largest Classes Eudicots Monocots Roses, sunflowers, maples
Herbaceous or woody
Branched veins
Flowers – multiples of 4 or 5
Seed – 2 cotyledons
Monocots
Grasses, corn, palms
Mainly herbaceous
Parallel veins in leaves
Flower parts – multiples of 3
Seed – 1 cotyledon, endosperm

4. Flowers Reproductive part of angiosperms
4 parts: sepals, petals, stamens, carpels
Complete vs. Incomplete flowers
Perfect vs. Imperfect flowers

6. Reproduction Pollination Double Fertilization Germination Wind Water
Pollinators
Double Fertilization
Germination

7. What happens in the anther?
Pollen sac contains many microsporocytes
Meiosis  4 haploid microspores
Each microspore  pollen grain (immature male gametophyte
Each pollen grain contains 2 cells:
Tube cell
Generative cell
Anther splits – sheds pollen

9. What happens in the pistil?
Each ovule in ovary contains megasporocyte
Meiosis  4 haploid megaspores
3 megaspores disintegrate
Remaining megaspore divides  gametophyte (aka embryo sac)
Gametophyte contains 7 cells w/ 8 nuclei
Egg cell contains 1 nucleus
Large center cell contains 2 polar nuclei

11. Double Fertilization Pollen lands on sticky stigma
Tube cell forms pollen tube through style into ovary
Generative cell divides  2 sperm cells
Double Fertilization
1 sperm fertilizes egg  zygote  embryo
1 sperm fuses with both polar nuclei  3n cell  endosperm

12. Seed and Fruit Formation
Ovule develops into seed
Ovary wall enlarges
Ripens into fruit
Flower parts fall off
Fruits:
Protect seeds from dessication
Aid in dispersal

13. Success of Flowering Plants
Seeds an advantage over spores
Cross-pollination – increases variation
Animals disperse pollen and fruit farther than wind

14. Adaptability of sporophyte generation
Efficient xylem
Vessel elements
Broad leaves
efficient photosynthesis
Abscission
Reduces water loss
Adaptability of sporophyte generation