Biological Classification (Chapter 2)

Vocabulary flashcards covering key terms and definitions from the notes on the history and concepts of biological classification, Whittaker's five-kingdom system, the five kingdoms and their characteristics, major subgroups, reproduction, and allied organisms.

Aristotle's approach to classification

Early scientific basis using simple morphological characters; plants categorized as trees, shrubs, herbs; animals divided into red-blooded vs non-red-blooded groups.

Linnaeus' Two-Kingdom system

Classification into Plantae and Animalia; did not distinguish between prokaryotes/eukaryotes, unicellular/multicellular, or photosynthetic/non-photosynthetic organisms.

Whittaker's Five Kingdom Classification

Five kingdoms: Monera, Protista, Fungi, Plantae, Animalia; criteria included cell structure, body organization, nutrition, reproduction, and phylogenetic relationships.

Three-Domain/Six-Kingdom note

Idea that Monera can be split into two domains, leaving other eukaryotic kingdoms in a third domain; concept leads toward a six-kingdom framework discussed in higher classes.

Kingdom Monera

Bacteria; prokaryotic; cell walls typically lack cellulose; includes autotrophs and heterotrophs.

Archaebacteria

Live in extreme habitats; distinct cell wall; examples include methanogens, halophiles, thermoacidophiles; methanogens produce methane in ruminants.

Eubacteria (true bacteria)

Rigid cell wall; cyanobacteria; diverse metabolisms (photosynthetic autotrophs, chemosynthetic autotrophs, heterotrophs); enzymes and roles in nitrogen cycling.

Cyanobacteria (blue-green algae)

Photosynthetic autotrophs with chlorophyll a; can be unicellular, colonial, or filamentous; some fix atmospheric nitrogen in heterocysts.

Mycoplasma

Lack of a cell wall; among the smallest living cells; can survive without oxygen; some are pathogenic.

Kingdom Protista

All single-celled eukaryotes (boundaries not well defined); includes Chrysophytes, Dinoflagellates, Euglenoids, Slime Moulds, Protozoans; mainly aquatic.

Chrysophytes

Diatoms and golden algae; silica cell walls; diatomaceous earth; important aquatic producers.

Dinoflagellates

Mostly marine and photosynthetic; two flagella; cellulose plates; red tides/biotoxins.

Euglenoids

Euglena; pellicle instead of a cell wall; two flagella; mixotrophic (photosynthetic in light, heterotrophic in dark).

Slime Moulds

Saprophytic protists; move as plasmodium; form spores with true walls; resistant to unfavorable conditions.

Protozoans

Heterotrophs; four major groups: Amoeboid, Flagellated, Ciliated, Sporozoans; examples include Amoeba, Trypanosoma, Paramecium, Plasmodium.

Kingdom Fungi

Heterotrophic; diverse morphology and habitats; chitin in cell walls; hyphae and mycelium; saprophytes and parasites; lichens and mycorrhizae; reproduce by spores.

Hyphae

Thread-like filaments; can be septate or coenocytic (lacking septa).

Mycelium

Network of hyphae forming the main body of a fungus.

Chitin

Primary component of fungal cell walls.

Fungal Reproduction (general)

Asexual spores (conidia, sporangiospores, zoospores) and sexual spores (oospores, ascospores, basidiospores) produced in fruiting bodies.

Phycomycetes

Aseptate/coenocytic mycelium; aquatic/damp habitats; sporangia produce zoospores or aplanospores; zygospore forms by fusion.

Ascomycetes

Sac-fungi; septate hyphae; asexual spores (conidia) on conidiophores; sexual spores (ascospores) in asci within ascocarps; examples include Aspergillus and Neurospora.

Basidiomycetes

Mushrooms, bracket fungi, puffballs; septate mycelium; basidia produce basidiospores on basidiocarps; examples Agaricus, Puccinia.

Deuteromycetes

Imperfect fungi; no known sexual stage; later moved to Ascomycetes or Basidiomycetes; reproduce mainly by conidia.

Kingdom Plantae

Eukaryotic, chlorophyll-containing organisms; cellulose cell walls; includes algae, bryophytes, pteridophytes, gymnosperms, angiosperms.

Alternation of Generations

Life cycle with alternating diploid sporophyte and haploid gametophyte generations; durations vary by group.

Kingdom Animalia

Heterotrophic, eukaryotic, multicellular; no cell walls; holozoic nutrition; glycogen/fat storage; diverse growth, senses, and movement; sexual reproduction with embryology.

Viruses, Viroids, Prions, Lichens (in context of classification)

Whittaker's system excludes acellular entities; viruses are non-cellular obligate parasites with nucleoprotein genomes; viroids are small infectious RNAs; prions are misfolded proteins; lichens are symbiotic associations between algae (phycobiont) and fungi (mycobiont).

Lichens

Symbiotic mutualism between algae (phycobiont) and fungi (mycobiont); algae provide food, fungi provide shelter and mineral uptake.

Diatoms/Di atomaceous Earth

Chrysophyte group with silica-based cell walls; form vast deposits called diatomaceous earth used in polishing and filtration; major ocean producers.

Karyogamy

Fusion of two nuclei during fungal sexual reproduction.

Plasmogamy

Fusion of cytoplasm between two compatible gametes in fungi.

Dikaryon

A stage in some fungi where cells contain two genetically distinct nuclei (n + n) before karyogamy.

Ascus and Ascocarps

In Ascomycetes, asci are sac-like structures containing ascospores; ascocarps are fruiting bodies bearing asci.

Basidium and Basidiocarps

In Basidiomycetes, basidia produce basidiospores externally on basidiocarps.