Seed Plants: Angiosperms Chapter 23 Lecture Outline Seed Plants: Angiosperms Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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

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 ?.

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.

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.

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

Lilly Pistil

Middle of Ovary

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

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

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.

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 ________.

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

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.

Phylum Magnoliophyta Lifecycle of typical flowering plant:

Phylum Magnoliophyta specialization: Inferior ovary Superior ovary

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

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

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

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

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

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

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

Herbaria: