1. Seed Plants
Chapter 30

2. Seed Plants Gymnosperms vs Angiosperms Gymnosperms
3 Major evolutionary changes in gymnosperms
Further decrease in prominence of the gametophyte generation
Pollination
Evolution of the seed

4. 5 Crucial Seed Plant Adaptations
1. Reduced gametophyte
Now gametophyte is dependent on sporophyte
Unlike in ________, where ________________
2. Heterospores
Megaspores = produce female gametophyte  eggs
Microspores = produce male gametophyte  sperm
3. Ovules and production of eggs
Protection of egg and developing zygote
Increases reproductive fitness (likelihood of successful production of offspring)

5. 4 & 5 Crucial Adaptations 4. Pollen & sperm production 5. Seeds
Pollen grain contains sperm nuclei
Pollen grain has waterproof coating
No more water needed for sperm to travel to the egg
Now it is the wind that disperses sperm
5. Seeds
Seeds > spores
Multicellular
Layers of protective tissue
Stored energy for the development of the embryo

7. Ovule to Seed Megaspore = Female spore (heterosporous)
-- Megaspore  female gametophyte
-- Female gametophyte produces egg (n)
-- Female gametophyte becomes nutrition for
developing embryo

8. Gymnosperms “naked” seeds Conifers (Coniferophyta)
Not enclosed in ovaries (fruits)
Seeds are typically in cones that allow for airborne dispersal
Conifers (Coniferophyta)
Pines, spruces, firs, and redwoods

9. Conifers have Ovulate & Pollen cones
Megasporangium undergoes meiosis = 4 haploid cells, but only 1 becomes megaspore
Multiple archegonia are produced inside each gametophyte = multiple eggs produced
Only 1 fertilized egg develops into the embryo, others dissolve

10. Gymnosperm Life Cycle Notes
Megasporangium (2n) – produces 4 megaspores (n)
Via meiosis
3 spores (n) dissolve leaving 1 megaspore
Megaspore (n) – develops into the female gametophyte (n)
Female gametophyte contains multiple archegonia
Multiple egg production
Sperm nuclei from pollen fertilizes egg(s)
Only one fertilized egg is able to survive

11. Questions?
What is the correct term for the pine tree? Diploid or haploid?
What is the correct term for the cones on the pine tree? Diploid or haploid?
Yellow cones are_______, pine cones are _______
How is the pollen dispersed?
What does the pollen produce?

12. What becomes of … ? Megasporangium? Megaspore? Egg, if fertilized?
Ovule?
Female gametophyte?

13. Angiosperms Fruits, Flowers, and double Fertilization
90% of all plant species
Seeded + Vascular
Flower – structure for sexual reproduction
Fruits – mature plant ovaries (yes, you are eating plant ovaries)
Double fertilization
1 sperm fertilizes egg = zygote
1 sperm combines with 2 nuclei in ovule = endosperm

14. Angiosperms – 2 classes Monocots Dicots (Eudicots)
Monocots have 1 cotyledon (structure that nourishes the developing plant)
Parallel veination in leaves
Orchids, lillies, and grasses
Dicots (Eudicots)
2 cotyledons in the seed
Netted veination in leaves
Roses, peas, beans, oaks

15. Stamen = Male
-- Anther + filament
-- Microspores produced in anther
Carpel = female
-- Ovary
-- Stigma, style
-- Megaspores produced in Ovules inside Ovary
Petals – attract pollinators

16. Fruits -- Can be wet or dry
-- Wet fruits – oranges, plums, grapefruit, tomatoes
-- Dry fruits – Beans, nuts, & grains

18. Life Cycle Notes Male gametophytes and are inside pollen grains
Microspore  pollen grain (n)
No real antheridia to speak of
Megasporangia produce megaspores (n)  female gametophyte  eggs ‘n stuff
Double fertilization
After male gametophyte produces pollen tube
1 nuclei fertilizes egg cell = zygote
1 nuclei fertilizes 2 nuclei in ovule = 3n endosperm