BIO 1407 : The Evolution of Seed Plants (Chapter 30)

Seed Plants

Plants with seeds, evolved from vascular plants.

Sporophyte Dominance

Seed plants primarily exhibit sporophyte generation.

Gametophyte

Microscopic structure retained inside sporangia.

Heterospory

Production of two types of spores.

Pollen

Male gametophyte, carried by wind or animals.

Fruits

Mature ovary that aids in seed dispersal.

Megasporangium

Structure producing megaspores in female plants.

Microsporangium

Structure producing microspores in male plants.

Ovule

Structure containing integument, megasporangium, and megaspore.

Pollination

Transfer of pollen to ovule for fertilization.

Zygote

Fertilized egg that develops into an embryo.

Gymnosperms

Seed plants with exposed seeds, not enclosed.

Angiosperms

Seed plants with fruits and flowers.

Coniferophyta

Largest gymnosperm phylum, includes conifers.

Cycadophyta

Phylum of gymnosperms with palm-like leaves.

Ginkgophyta

Phylum containing only Ginkgo biloba species.

Gnetophyta

Phylum of gymnosperms with diverse species.

Pollen Cone

Cone containing microsporangia for pollen production.

Ovulate Cone

Cone containing megasporangia that produce eggs.

Sequoiadendron giganteum

Largest living organisms, known as Sequoias.

Pseudotsuga menziesii

Douglas fir, major timber source in North America.

Cycas revoluta

Cycad species with flagellated sperm.

Ginkgo biloba

Only surviving Ginkgo species, pollution tolerant.

Ephedra

Genus with desert species, produces ephedrine.

Magnoliophyta

Single phylum containing all angiosperms.

Stamen

Male reproductive organ, includes anther and filament.

Carpel

Female reproductive organ, includes stigma and ovary.

Fertilization

Process where sperm fertilizes the ovule.

Fruit

Developed from ovary, protects seeds.

Angiosperm Importance

Source of most human food and livestock feed.

Edible Products

Common foods derived from angiosperms include cacao and coffee.

Medicinal Uses

Angiosperms provide compounds like aspirin and quinine.

Threats to Diversity

Human population expansion threatens plant diversity.