1. Kingdom Plantae
Angiosperms

3. History Oldest known fossils date back to about 132 million years ago
Molecular data show they evolved around 125 – 180 million years ago
Co-evolved with flying insects as polinators

4. General Characteristics
Produce covered seeds that are enclosed in a fruit
Flowering plants include many species of trees, shrubs, flowers, vegetables, and grasses
Are the most widespread of all land plants and are found in all types of habitats
Sporophyte generation is dominant
Have coevolved with insects to help pollination
Dominate the earth’s surface compared to other plants

5. Unique Characteristics
Fruits and Flowers!!
These two structures are key to angiosperm success
Flowers attract pollinators allowing for greater genetic distribution; pollination does not depend on the randomness of the wind
Fruits attract predators. The seed within a fruit typically can withstand being digested so seeds are dispersed in animal feces (comes with it’s own fertilizer!)
Flowers also contain ovaries which surround and protect the seeds

6. Structure

8. Leaves

9. Flowers A. Female Reproductive Structures
Pistil: Contains the stigma, the style and the ovule(s) within the ovary
Stigma: Captures and traps the pollen with a sticky or hairy substance
Style: Allows the pollen tube to travel down to the ovule
Ovary: Encloses and surrounds the ovule
Contains one or more ovules for double fertilization
The ovule contains the female gametophyte and the polar nuclei

11. Flowers B. Male Reproductive Structures
Stamen: Contains the anther and the filament
Anther: Undergoes meiosis producing pollen grains
Filament: Supports the anther
C. Other Parts
Receptacle: The base where the petals, ovary and sepals are attached
Sepals: They are green and they enclose and protect the developing flower
Petals: They are brightly coloured and scented to attract insects, bats and birds

15. Flower Reproduction
The Anther produces pollen which contains two male gametes (sperm)
The pollen is picked up by a pollinator or by the wind and travels to another flower where it sticks to the stigma (it is sticky)
The pollen grain grows a pollen tube down the through the stigma, down the style, and to the ovary
The sperm travel down the tube and double fertilization occurs

16. The two sperm fertilize different structures in the ovary.
One sperm fertilizes the egg (N + N = 2N) to produce the zygote (baby plant)
The other sperm fertilizes the endosperm which has NOT undergone meiosis and is thus 2N + N = 3N.
Endosperm provides nutrition for the developing embryo

17. Diversity Angiosperms are categorized in many ways:
monocots and dicots
woody and herbaceous plants
annuals, biennials, and perennials
An angiosperm can belong to more than one category.

19. Monocots and Dicots
Monocots and dicots are named for the number of seed leaves, or cotyledons, in the plant embryo. Monocots have one seed leaf, and dicots have two.
A cotyledon is the first leaf or the first pair of leaves produced by the embryo of a seed plant.

22. Woody vs Herbaceous Plants
Plant stems that are smooth and nonwoody are characteristic of herbaceous plants.
Woody plants include trees, shrubs, and vines.

23. Annuals, Biennials, and Perennials
Annuals are plants that complete a life cycle in one growing season.
Biennials complete their life cycle in two years. In the first year, they germinate and grow roots, short stems, and sometimes leaves. In the second year, they grow new stems and leaves, produce flowers and seeds, and die.
Perennials live for more than two years.

25. Evolutionary Adaptations
Vascular Tissues
Xylem: Tracheids and vessel elements transport H2O and nutrients to the plant
Phloem: Sieve tubes transport sugars from photosynthesis to the rest of the plant
B. Meristems
Apical and lateral meristems provide growth in height, length, and width of roots and stems

26. More
Dominant sporophyte generation produces and protects the male and female gametophytes
Broad leaves have great surface area for photosynthesis and are covered by a waxy cuticle to prevent H2O loss
Leaves have stomata to prevent H2O loss and regulate gas exchange

27. Ecological Significance:
Are a dominant sourced of food in the food chain
Fruit, nectar, herbaceous vegetation…
Dominant Land Plant so they contribute greatly to global oxygen levels
Decrease Greenhouse Gases
Provide Habitat (huge significance – some organisms ONLY ever live in the trees)
Provide minerals to the soil (Alders have symbiotic relationship with bacterium that fixes nitrogen)
Close ecological symbiotic relationships with other organisms such as pollinators
Important in the water cycle due to transpiration

28. Economic Importance Food crops (fruit and vegetables)
Are a source of pulp for paper products
Used as a fuel source
Provide wood for homes and shelter
Source of fabric