1. Seed Plants: Angiosperms
Chapter 23
Lecture Outline
Seed Plants: Angiosperms
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2. Outline Introduction Phylum Magnoliophyta – The Flowering Plants
Development of Gametophytes
Pollination
Fertilization and Development of the Seed
Apomixis and Parthenocarpy
Trends of Specialization and Classification in Flowering Plants
Pollination Ecology
Herbaria and Plant Preservation

3. Introduction Angiosperms = Phylum Magnoliophyta– formerly ANTHOPHYTA.
- Presence of __________
which is a modified stem bearing modified leaves.
Carpel/Pistil modified leaf that has folded over and fused at margins. Holds ?
Pistil composed of 1 or more carpels
Bleeding hearts
Seed develops from ?
Ovary develops into ?.

4. Phylum Magnoliophyta – The Flowering Plants
Heterosporous =
Dominant part of Life Cycle?
Female gametophytes size and location:
Male gametophytes =
Development of Female Gametophytes
Megasporangium has Megasporocytes that differentiates in ovule.
Undergoes meiosis and produces ?
Three degenerate.

5. Phylum Magnoliophyta
Remaining Megaspore enlarges and nucleus divides to produce 8 nuclei (without walls). =
Outer two layers of ovule differentiate into integuments that later become seed coat.
Micropyle at one end of ovule
8 nuclei form two groups, 4 near each end of cell.
One nucleus from each group migrates to cell middle and form central cell.

6. Phylum Magnoliophyta Cell walls form around remaining six nuclei.
Egg and two synergids closest to micropyle
Three antipodals at opposite end - No apparent function
Female gametophyte (megagametophyte, embryo sac) = large sac containing 8 nuclei and 7 cells

7. Lilly Pistil

8. Middle of Ovary

9. Anther with microspores
Phylum Magnoliophyta
Development of gametophytes - Male:
Male gametophytes for in _______________
Pollen sacs, of microsporocyte cells differentiate there
Each microsporocyte undergoes meiosis to produce ?.
Anther with microspores

10. Phylum Magnoliophyta Development of gametophytes - Male:
Microspores form _____________:
Forms a small generative cell inside the larger tube cell
Nucleus of tube cell = vegetative nucleus
Pollen Wall becomes two- layered.
Outer layer = exine
Finely sculptured
Contains chemicals that may react with chemicals in stigma
Generative nucleus later forms __________
Pollen grain

11. Phylum Magnoliophyta Pollination:
Pollination - Transfer of pollen grains from _____
Fertilization =
Pollination by insects, wind, water, animals or gravity.
After pollination, further development of male gametophyte may not take place unless pollen grain is:
From a different plant of the same species.
From a variety different from that of the receiving flower.

12. Fertilization and development of the seed:
Phylum Magnoliophyta
Fertilization and development of the seed:
Pollen tube:
Generative cell:
Pollen tube enters female gametophyte and discharges ________.

13. Phylum Magnoliophyta Fertilization and development of the seed:
Mature male gametophyte = germinated pollen grain with its vegetative nucleus and two sperms within tube cell

14. Phylum Magnoliophyta Fertilization and development of the seed:
Double fertilization:
One sperm unites with:
Other sperm unites with: central cell nuclei, producing triploid endosperm nucleus that develops into endosperm tissue.
Endosperm tissue =
Ovule becomes seed, ovary matures into fruit, integuments harden into seed coat.

15. Phylum Magnoliophyta
Lifecycle of typical flowering plant:

16. Phylum Magnoliophyta
specialization:
Inferior ovary
Superior ovary

17. Female flower with inferior ovary
Phylum Magnoliophyta
Flower:
Male flower
Female flower with inferior ovary
Complete –
Incomplete –
Perfect –
Imperfect –
Monoecious –
Dioecious -

18. Phylum Magnoliophyta Primitive Plants: Leaves: Simple Fusion: NO
Symmetry: regular
Magnolia
Flowers Complete & perfect
Ovary– superior
Modern Plants
Symetry: bilateral
Orchid

19. Pollination Ecology Pollinators have coevolved with plants.
Bee-pollinated flowers:
Color: mostly blue or yellow
lines function as guides to pollen/nectar.
UV light
Smell- sweet
In ordinary light
In UV light

20. Pollination Ecology Beetle-pollinated flowers: Fly-pollinated flowers:
Strong, yeasty, spicy or fruity odor
White or dull color
Fly-pollinated flowers:
rotten meat
Dull red or brown

21. Pollination Ecology Butterfly- and moth-pollinated flowers:
sweet fragrances
White/yellow: nocturnal
red, blue, yellow, orange: butterflies
Tubular flowers.
Bird-pollinated flowers (hummingbirds and sunbirds):
red or yellow
no odor
Tubular
Copious nectar

22. Pollination Ecology Bat-pollinated flowers: tropics Open at night Dull
Large for insert head

23. Pollination Ecology Orchid flowers: Pollen grains in pollinia-sticky
Ophrys: resembles female bee/wasp.
Male copulate with flower.
Ophrys

24. Herbaria: