Secrets of Gymnosperms: Seed Production and Advantages

1. Gymnosperms

2. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit

3. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit • Examples: • Cycads

4. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit • Examples: • Cycads • Ginko

5. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit • Examples: • Cycads • Ginko • Conifers

6. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit • Examples: • Cycads • Ginko • Conifers • Angiosperms • Seeds covered by fruit

7. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit • Examples: • Cycads • Ginko • Conifers • Angiosperms • Seeds covered by fruit • Examples: • Monocots Daffodils

8. Group 3: Seed producing, Vascular Plants • Gymnosperms • Seeds not covered by fruit • Examples: • Cycads • Ginko • Conifers • Angiosperms • Seeds covered by fruit • Examples: • Monocots • Dicots Apple flowers

9. Seeds and their advantages Seed plants don’t depend on water to reproduce Pollen (contains sperm) carried by wind/animals Embryo has… Nourishment: Nutrients inside feed embryo Protection: Hard shell Allow dispersal Carried by wind, water, animals Some seeds have “wings” Some seeds are “dispersed” by animals

10. Seeds and their advantages • Seed plants don’t depend on water to reproduce • Pollen (contains sperm) carried by wind/animals • Embryo has… • Nourishment: Nutrients inside feed embryo • Protection: Hard shell • Allow dispersal • Carried by wind, water, animals Helicopter seed falling

11. Seeds and their advantages • Seed plants don’t depend on water to reproduce • Pollen (contains sperm) carried by wind/animals • Embryo has… • Nourishment: Nutrients inside feed embryo • Protection: Hard shell • Allow dispersal • Carried by wind, water, animals Many helicopter seeds falling

12. Conifers Type of gymnosperm Needle-like leaves (reduces water loss) Common to lumber industry Cones used to reproduce Male pollen cones: produce pollen Female seed cones: produce eggs Embryo grows inside seed Ex: Evergreen, Pine, Redwood, Cedar

13. Conifer Life Cycle • Mature Sporophyte creates cones: • Pollen cones (male) • Microspores created by meiosis • Microspores develop into pollen • Pollen = male gametophyte . Pollen cones . . . . Seed cone Pollen released into the air

14. Conifer Life Cycle Let’s look at one scale • Mature Sporophyte creates cones: • Pollen cones (male) • Microspores created by meiosis • Microspores develop into pollen • Pollen = male gametophyte • Seed cones (female) • Megaspore created by meiosis • Megaspore grows to become female gametophyte • Egg inside female gametophyte Female gametophyte Pollen cones Seed cone

15. Conifer Life Cycle . • Mature Sporophyte creates cones: • Pollen cones (male) • Microspores created by meiosis • Microspores develop into pollen • Pollen = male gametophyte • Seed cones (female) • Megaspore created by meiosis • Megaspore grows to become female gametophyte • Egg inside female gametophyte • Pollination • Pollen tube grows towards egg Female gametophyte Sperm cell pollen

16. Conifer Life Cycle • Mature Sporophyte creates cones: • Pollen cones (male) • Microspores created by meiosis • Microspores develop into pollen • Pollen = male gametophyte • Seed cones (female) • Megaspore created by meiosis • Megaspore grows to become female gametophyte • Egg inside female gametophyte • Pollination • Pollen tube grows towards egg • Fertilization • Sperm travels down pollen tube to fertilize egg • Zygote grows into embryo • Seed coat hardens • Seeds released & can grow into young sporophyte Seeds inside every scale Sperm cell . pollen seed Let’s go back to the seed cone

17. Conifer Life Cycle • Mature Sporophyte creates cones: • Pollen cones (male) • Microspores created by meiosis • Microspores develop into pollen • Pollen = male gametophyte • Seed cones (female) • Megaspore created by meiosis • Megaspore grows to become female gametophyte • Egg inside female gametophyte • Pollination • Pollen tube grows towards egg • Fertilization • Sperm travels down pollen tube to fertilize egg • Zygote grows into embryo • Seed coat hardens • Seeds released & can grow into young sporophyte

18. Conifer Life Cycle • Mature Sporophyte creates cones: • Pollen cones (male) • Microspores created by meiosis • Microspores develop into pollen • Pollen = male gametophyte • Seed cones (female) • Megaspore created by meiosis • Megaspore grows to become female gametophyte • Egg inside female gametophyte • Pollination • Pollen tube grows towards egg • Fertilization • Sperm travels down pollen tube to fertilize egg • Zygote grows into embryo • Seed coat hardens • Seeds released & can grow into young sporophyte Pollen cone Seed cone

19. Review • How are angiosperms different from gymnosperms? • Name three advantages of seeds. • Which structure will protect and release gymnosperm seeds? • What are male cones called and what do they produce? • What are female cones called and what do they produce? • What is created when the sperm and egg fuse: sporophyte or gametophyte?