Plant Diversity I: Introduction to Kingdom Plantae

Vocabulary flashcards covering algal ancestry, derived land plant adaptations, bryophyte life cycles, nonvascular plant diversity, and seedless vascular plant traits.

Charophytes

The green algae species identified as the closest living algal relatives of land plants.

Embryophytes

Multicellular photosynthetic eukaryotes (land plants) that use chlorophyll a and b, store carbohydrates, and develop from an embryo protected by the parent plant.

Alternation of Generations

A plant life cycle process in which organisms alternate between two multicellular generations: haploid gametophytes and diploid sporophytes.

Gametophyte

The multicellular haploid generation of a plant that produces haploid gametes (sperm and eggs) by mitosis.

Sporophyte

The multicellular diploid generation of a plant that produces haploid spores by meiosis.

Sporopollenin

A durable polymer present in charophyte zygote walls and plant spore walls that prevents them from drying out and protects against harsh environments.

Apical Meristems

Localized regions of continuous cell division at the tips of roots and shoots that enable elongation for better resource acquisition.

Cuticle

A waxy covering on the epidermis of land plants that acts as waterproofing to reduce water loss.

Stomata

Specialized pores in plant tissues that open and close to facilitate gas exchange between the outside air and internal plant tissues.

Mycorrhizae

Symbiotic associations formed between plant roots and soil fungi that helped early land plants absorb nutrients.

Bryophytes

An informal name for nonvascular land plants, comprising liverworts (Hepatophyta), mosses (Bryophyta), and hornworts (Anthocerophyta).

Rhizoids

Long, tubular single cells or filaments of cells that anchor gametophytes of nonvascular plants to substrate without playing a primary role in water/nutrient absorption.

Archegonia

Female gametangia in plants that produce nonmotile eggs and serve as the site of fertilization.

Antheridia

Male gametangia in plants that produce and release flagellated sperm.

Protonema

A mass of green, branched, one-cell-thick filaments produced when a moss spore germinates.

Gametophore

The mature gamete-producing structure of a moss gametophyte generated from apical buds on a protonema.

Peristome

A ring of interlocking, tooth-like structures specialized for gradually releasing spores under dry conditions at the top of a moss capsule.

Xylem

Vascular plant tissue that conducts water and minerals upward from roots, containing polymer lignin in its cell walls for structural support.

Phloem

Vascular plant tissue consisting of living cells arranged into tubes that transport sugars, amino acids, and other organic nutrients throughout the plant.

Microphylls

Small, usually spine-shaped leaves supported by a single unbranched vein, found uniquely in lycophytes.

Megaphylls

Leaves with a highly branched vascular system that support greater photosynthetic capacity.

Sporophylls

Modified leaves that carry sporangia for spore production.

Strobili

Technical term for cone-like structures formed by clusters of sporophylls in gymnosperms and lycophytes.

Sori

Clusters of sporangia located on the undersides of fern sporophyll leaves.

Homosporous

Plant species producing a single type of spore that typically develops into a bisexual gametophyte.

Heterosporous

Plant species producing two morphologically distinct types of spores: megaspores that develop into female gametophytes and microspores that develop into male gametophytes.