Classification of Plant Kingdom and Living Organisms

Comprehensive vocabulary flashcards covering the seven kingdom classification of life, comparative plant characteristics, algae, fungi, bryophytes, pteridophytes, gymnosperms, and angiosperms.

Kingdom Archaea

A group of primitive, extremophilic unicellular prokaryotes characterized by cell membranes with unique ether-linked lipids and cell walls that completely lack peptidoglycan.

Kingdom Bacteria

"True" standard bacteria possessing cell walls composed of peptidoglycan (murein) and cell membranes containing standard ester-linked lipids.

Kingdom Protista

A eukaryotic kingdom composed of unicellular or colonial organisms lacking cell walls that are predominantly heterotrophic and feed via phagocytosis.

Kingdom Chromista

Photosynthetic eukaryotes containing chlorophyll a and c (never chlorophyll b) whose chloroplasts are uniquely wrapped within an extra, outer membrane layer.

Kingdom Fungi

Unicellular or multicellular organisms possessing chitin-containing cell walls that function strictly as absorptive heterotrophs by secreting extracellular enzymes.

Kingdom Plantae

Multicellular, cellulose-walled, autotrophic embryophytes possessing chlorophyll a and b that protect early embryos within maternal tissues and exhibit alternation of generations.

Kingdom Animalia

Multicellular, tissue-bearing, ingestive heterotrophs lacking cell walls that typically exhibit high mobility using a specialized neuromuscular system.

Alternation of Generations

The distinct life cycle of true plants that continuously shifts between a multicellular haploid gametophyte phase ($n$) and a multicellular diploid sporophyte phase ($2n$).

Gametophyte

The haploid ($n$) sexual generation in plants that produces gametes via mitosis within sex organs termed the antheridium (male) and archegonium (female).

Sporophyte

The diploid ($2n$) asexual generation resulting from gamete fusion that produces haploid spores through meiosis within sporangia.

Haplontic Life Cycle

A life cycle in which the main plant body is haploid (gametophyte) and the zygote represents the only diploid stage, as seen in Volvox and Spirogyra.

Diplontic Life Cycle

A life cycle where the dominant plant body is diploid (sporophyte) and gametes represent the only haploid stage, typical of gymnosperms and angiosperms.

Pyrenoid

A specialized sub-cellular protein center located within algal plastids around which starch reserves are packaged and stored.

Chlorophyceae

Green algae containing chlorophyll a and b, possessing cell walls of inner cellulose and outer pectose, storing starch around pyrenoids, and bearing 2 to 8 equal apical flagella.

Phaeophyceae

Brown algae containing chlorophyll a, c, and fucoxanthin, coated by alginic acid and fucoidan, storing laminarin or mannitol, and bearing 2 unequal lateral flagella.

Rhodophyceae

Red algae containing the phycobilin pigment r-phycoerythrin, complex cell walls yielding agar-agar and carrageenan, storing floridean starch, and entirely lacking motile cells.

Bryophytes

Non-vascular land plants referred to as the amphibians of the plant kingdom because they require a film of external water for flagellated sperm to reach the archegonium.

Hepaticopsida

A class of bryophytes (liverworts) with thalloid or foliose gametophytes, unicellular unbranched rhizoids, capsules lacking a columella, and elaters with spiral thickenings.

Anthocerotopsida

A class of bryophytes (hornworts) containing a single large chloroplast with a pyrenoid per cell, an elongated capsule with a basal meristem, a central columella, and pseudo-elaters.

Bryopsida

The class of true mosses characterized by a juvenile protonema stage, adult leafy gametophores with multicellular oblique rhizoids, and capsules regulated by peristome teeth.

Coenocytic Hyphae

Aseptate fungal filaments lacking cross-walls where the cytoplasm is continuous and contains numerous free-floating nuclei.

Haustoria

Specialized hyphal penetrating organs utilized by parasitic fungi to absorb nutrients directly from the living cells of host tissues.

Zygomycota

Conjugation fungi with coenocytic mycelia and chitin-chitosan walls that reproduce sexually via gametangial copulation to form a thick-walled resting zygospore.

Ascomycota

Sac fungi featuring septate hyphae with simple pores that reproduce sexually by producing endogenous ascospores (typically 8) inside a microscopic sac called an ascus.

Ascocarp

The specialized fruiting body in sac fungi housing asci, taking forms such as a closed cleistothecium, an ostiolate perithecium, or an open cup-shaped apothecium.

Basidiomycota

Club fungi featuring dolipore septa with parenthesomes, clamp connections, and sexual reproduction yielding exogenous basidiospores (typically 4) on sterigmata of a basidium.

Clamp Connection

A distinctive lateral loop-like hyphal structure formed during cell division in secondary basidiomycete mycelium to ensure proper segregation of paired dikaryotic nuclei.

Deuteromycota

An artificial taxonomic form-class of fungi (Fungi Imperfecti) with septate hyphae that lack an observed sexual cycle and reproduce exclusively by conidia.

Parasexual Cycle

A non-sexual mechanism in imperfect fungi involving vegetative nuclear fusion, mitotic crossing over, and haploidization that creates genetic variation without true meiosis.

Pteridophytes

Vascular cryptogams with a dominant, free-living diploid sporophyte ($2n$) possessing tracheids and sieve cells, requiring external water for flagellated antherozoids to fertilize eggs.

Prothallus

The small, inconspicuous, autotrophic, multicellular haploid gametophyte ($n$) produced by a germinated pteridophyte spore.

Psilophyta

A primitive division of rootless vascular cryptogams bearing subterranean rhizomes, erect dichotomous stems, a protostele, and sporangia fused into a trilobed synangium.

Lycophyta

A division of pteridophytes possessing microphyllous leaves, terminal strobili, and in certain genera, specialized prop-like rhizophores and ligulate leaves.

Sphenophyta

Horsetails displaying jointed stems with ribbed silica-rich internodes, whorled scaly leaves, and peltate sporangiophores producing spores equipped with hygroscopic elaters.

Circinate Vernation

The distinctive coiled, unrolling developmental posture exhibited by young megaphyllous fern fronds.

Sori

Aggregated clusters of sporangia located on the abaxial surface or margins of fertile fern fronds, often sheltered beneath a protective flap called an indusium.

Gymnosperms

Woody perennial plants characterized by naked ovules borne exposed on reproductive scale surfaces without enclosure inside an ovary.

Siphonogamy

The reproductive mechanism in seed plants where non-motile or motile male gametes are conveyed to the female gametophyte via the elongation of a pollen tube.

Coralloid Roots

Specialized, dichotomously branched, apogeotropic roots in cycads that grow near the soil surface and host nitrogen-fixing Anabaena cyanobacteria.

Order Coniferales

An order of evergreen gymnosperms characterized by monopodial growth, pycnoxylic wood, needle-like foliage, internal resin ducts, and ectomycorrhizal symbioses.

Order Gnetales

Advanced gymnosperms exhibiting angiosperm-like affinities, including true vessels in the xylem, flower-like compound strobili, and complete loss of archegonia in advanced taxa.

Double Fertilization

A defining angiosperm event wherein one sperm fertilizes the egg to form a diploid zygote ($2n$) and a second sperm fuses with two polar nuclei to yield triploid endosperm ($3n$).

Class Dicotyledonae

Angiosperms characterized by embryos with two cotyledons, reticulate leaf venation, taproot systems, tetramerous or pentamerous flowers, and vascular bundles in an open ring.

Class Monocotyledonae

Angiosperms possessing a single cotyledon, fibrous root systems, parallel venation, trimerous flowers, and scattered, closed vascular bundles (atactostele) lacking cambium.

Atactostele

The stem anatomy characteristic of monocots in which closed vascular bundles lacking cambium are scattered irregularly throughout the ground tissue.

Family Poaceae

The monocot grass family characterized by hollow jointed stems (culms), alternate leaves with sheathing bases and ligules, and wind-pollinated spikelet inflorescences.

Family Orchidaceae

An advanced monocot family characterized by aerial roots coated in velamen tissue, zygomorphic flowers with a specialized labellum, and pollen aggregated into pollinia.