Vascular Seed Plants

1. Vascular Seed Plants Plants that plan ahead…

2. Seeds – Overview and Structure Seed plants, perhaps unsurprisingly, produce… seeds. A seed is a structure that contains: • An immature sporophyte (remember – sporophytes often become the BIGGEST part of a more complex plant). • Food (carbs and fats) to keep it alive until it finds suitable growth conditions.

3. Types of Vascular Seed Plants • Further broken into two major groups: • Gymnosperms • Plants whose seeds are “exposed” (gymno = “naked”) as they develop on the mature sporophyte. • Angiosperms • Plants whose seeds develop in a closed ovary (this later develops into a fruit). - You read that correctly. We eat a balanced diet that includes a healthy amount of plant ovaries. Eat up!

4. Gymnosperms ‘tis the season!

5. Gymnosperms – Typical organisms • Coniferous trees – trees that put out cones that will store spores. • Eg: Spruce, pine, and fir • Found in nearly every climate (guess where it isn’t found!)

6. Typical Orgnisms cont’d • Ephedra sp. – smaller shrubs; produce compounds that have well-known medicinal uses. • Increase metabolism, heart rate, and ventilation (breathing). • Used to be used as performance-enhancing drugs. • Now banned in the US; highly controlled in Canada.

7. Typical Organisms cont’d • Cycads – resemble short, shrubby palm trees. • Date back to the same era as the dinosaurs. The Nomosaurus enjoying a light gymnosperm salad. Entrée of sauteed simians soon to follow.

8. Gymnosperm Structure • Needle-like leaves – small surface area, prevents loss of water and nutrients. • Many (NOT all) gymnosperms are “evergreens” – don’t drop their leaves.

9. Structure cont’d • Has roots which are seldom deep but cover a large area. • Produce cones which store and protect either male or female spores.

10. Structure cont’d • Gymnosperms are adapted for life on land. • Water needed for nutrition only – not for reproduction. Pollen can “fly”.

11. Gymnosperm Reproduction (Using conifers as our example) • Mature conifers make both male AND female cones. • Produce two types of spores – male and female, respectively. • Male spores = pollen; these spores are released. • Female spores NOT mobile. Remain in their cones. Fertilized by pollen that lands upon them.

12. Gymnosperm Reproduciton

13. Angiosperms Flower power, yo!

14. Angiosperms - Overview • All produce a flower (not necessarily a pretty one). • Adapted to rely on a variety of pollinators: • Wind • Insects • Larger animals • Enclose their seeds for protection (often in a fruit).

15. Angiosperm classification • Angiosperms are divided into two main groups. • Grouping is based on how many cotyledons (“seed leaves”) the plant makes. These are the first leaves the plant will make. • Monocots produce one cotyledon. • Dicots produce two cotyledons.

16. Monocot VS Dicot Monocots and dicots differ with respect to other features, too. These include: • Arrangement of xylem and phloem • Structure of “veins” in the leaves • Arrangement and structure of flowers

17. Monocot VS Dicot

18. Angiosperm Reproduction • Happens through pollination (sexual). • Involves male and female gametes. • The male gametes are always those that actually move from one place to another.

19. Angiosperm Reproduction cont’d • Some angiosperms carry BOTH male and female structures. • Called monoecious plants

20. Angiosperm reproduction cont’d • Other angiosperms only produce structures for a single gender (only male or only female). • These are called dioecious plants.

21. Angiosperm Reproduction cont’d

22. Angiosperm Reproduction cont’d • Pollination leads to formation of seeds. Seeds can spread through a few ways: • Attaching to animals (uses hooks and spines) • Seed explosions • Wind dispersal (using wings or “parachutes”)

23. Angiosperm Reproduction cont’d • Water • Animal digestion (from eating fruit)