Plant Evolution Flashcards

Vocabulary flashcards based on lecture notes about Plant Evolution.

Embrophyta

The plant clade. Land plants are the foundation of terrestrial life and arose from a lineage of freshwater multicellular green algae.

Streptophyte

The green algae that most closely resembles terrestrial land plants, sharing features like chlorophylls a and b, starch energy storage, and cell walls of cellulose and pectin.

Viridiplantae

The clade including all green algae and land plants.

Alternation of Generations

A conserved sexual life cycle pattern in all land plants, involving two alternating multicellular forms: diploid sporophyte (2n) and haploid gametophyte (n).

Sporophyte

The diploid (2n) multicellular form in plants that undergoes meiosis to produce haploid spores, which develop into gametophytes.

Gametophyte

The haploid (n) multicellular form in plants that produces gametes via mitosis.

Gametangia

Organs inside of which gametes are produced.

Sporangia

Organs inside of which spores are produced.

Cuticle

A waxy coating on land plants that slows water loss.

Stomata

Openings in stems and leaves of land plants that regulate gas exchange and conserve water.

Vascular Tissue

Plant tissue for transport and support.

Bryophytes

Informal taxonomic designation for early seedless non-vascular plants like liverworts, mosses, and hornworts.

Tracheophyta

The clade of plants that evolved vascular tissue.

Xylem

Vascular tissue that transports water and nutrients from the roots to the rest of the plant.

Phloem

Vascular tissue that transports sugars from photosynthetic to storage tissues.

Homosporous

Ancestral plants that produce only one type of spore.

Heterosporous

Plants that produce two types of spores: megaspores and microspores.

Megaspores

Spores produced by meiosis in megasporangia that develop into female gametophytes (megagametophytes) and produce eggs.

Microspores

Spores produced by meiosis in microsporangia that develop into male gametophytes (microgametophytes) and produce sperm.

Spermatophyta

The clade of plants known as seed plants.

Gymnosperms

The first spermatophytes to evolve, having 'naked seeds' not enclosed by surrounding structures (e.g., conifers, cycads, ginkgos, and gnetophytes).

Angiosperms

Flowering plants with seeds enclosed by the ovary of the flower.

Monocots

A major clade of angiosperms including grasses, cattails, lilies, orchids, and palms.

Eudicots

A major clade of angiosperms including most herbs, vines, trees, and shrubs.

Antheridium

Male reproductive organ (gametangium).

Archegonium

Female reproductive organ (gametangium).