Vocabulary Flashcards – Chapters 27, 28, 31 & 56

A comprehensive set of vocabulary flashcards covering major terms and concepts from the lecture notes on Bacteria & Archaea, Protists, Fungi, and Conservation Biology.

Prokaryote

Single-celled organism lacking a nucleus; includes bacteria and archaea.

Bacteria

One of the two prokaryotic domains; most abundant, diverse prokaryotes.

Archaea

Prokaryotic domain sharing traits with both bacteria and eukaryotes; many are extremophiles.

Coccus (plural Cocci)

Spherical-shaped prokaryotic cell.

Bacillus (plural Bacilli)

Rod-shaped prokaryotic cell.

Spirillum / Spiral

Helical or corkscrew-shaped prokaryotic cell.

Peptidoglycan

Polymer in most bacterial cell walls; thick in Gram-positive bacteria.

Gram-positive bacterium

Bacterium with thick peptidoglycan wall that stains purple in Gram stain.

Gram-negative bacterium

Bacterium with thin peptidoglycan layer and outer lipopolysaccharide membrane; stains pink.

Lipopolysaccharide

Molecule in outer membrane of Gram-negative bacteria; can act as endotoxin.

Capsule

Sticky polysaccharide layer outside some prokaryote cell walls; aids adhesion and immune evasion.

Endospore

Dormant, highly resistant cell produced by some bacteria to survive harsh conditions.

Fimbriae

Short, hair-like appendages that help prokaryotes adhere to surfaces or each other.

Pilus (plural Pili)

Longer appendage allowing DNA transfer during conjugation; also called sex pilus.

Taxis

Directed movement toward or away from a stimulus.

Flagellum (plural Flagella)

Whip-like structure used by many prokaryotes for motility.

Plasmid

Small, circular, independently replicating DNA ring in prokaryotes.

Rapid reproduction

Frequent binary fission in prokaryotes, contributing to genetic diversity.

Mutation

Random DNA change; main source of new genetic variation in prokaryotes.

Transformation

Uptake of naked foreign DNA from environment by a prokaryotic cell.

Transduction

Gene transfer between bacteria via bacteriophages (viruses).

Conjugation

Direct DNA transfer between bacterial cells connected by a mating bridge.

Horizontal gene transfer

Movement of genes between different species or individuals, not via inheritance.

Photoautotroph

Organism using light for energy and CO₂ as carbon source; e.g., cyanobacteria.

Chemoautotroph

Prokaryote using inorganic chemicals for energy and CO₂ for carbon.

Photoheterotroph

Organism using light for energy and organic compounds for carbon.

Chemoheterotroph

Organism obtaining both energy and carbon from organic compounds.

Obligate aerobe

Prokaryote that requires oxygen for cellular respiration.

Obligate anaerobe

Prokaryote poisoned by oxygen; uses fermentation or anaerobic respiration.

Facultative anaerobe

Prokaryote that can switch between aerobic and anaerobic metabolism.

Biofilm

Surface-coating microbial community of cooperating prokaryotes embedded in matrix.

Proteobacteria

Large, diverse phylum of Gram-negative bacteria defined by rRNA; includes E. coli and Rhizobium.

Chlamydias

Gram-negative intracellular bacterial parasites; e.g., Chlamydia trachomatis.

Spirochetes

Helical Gram-negative heterotrophic bacteria; include syphilis and Lyme disease agents.

Gram-positive bacteria

Group with thick peptidoglycan walls; includes Bacillus, Clostridium, Staphylococcus, Actinomycetes.

Extreme halophile

Archaeon thriving in highly saline environments.

Extreme thermophile

Archaeon thriving at very high temperatures.

Methanogen

Anaerobic archaeon producing methane from CO₂ and H₂; lives in guts and swamps.

Symbiosis

Close ecological relationship between two species living in contact.

Mutualism

Symbiosis where both partners benefit.

Parasitism

Symbiosis where one organism benefits at the host’s expense.

Bioremediation

Use of organisms, often prokaryotes, to remove pollutants from environment.

Exotoxin

Toxic protein secreted by bacteria that disrupts host cell function.

Endotoxin

Lipopolysaccharide toxin released when Gram-negative bacteria die.

Protist

Informal term for mostly unicellular eukaryotes; polyphyletic group.

Mixotroph

Protist combining photosynthesis and heterotrophy for nutrition.

Apicomplexan

Parasitic protist group with apex organelles for penetrating host cells.

Plasmodium

Apicomplexan parasite causing malaria in humans.

Malaria

Mosquito-borne disease caused by Plasmodium infection.

Ciliate

Protist using cilia for movement and feeding; most are predators.

Amoebozoan

Clade of amoebas with lobe-shaped pseudopodia; includes slime molds and Entamoeba.

Symbiont (protist)

Protist living in close, often mutualistic association with another organism.

Producer (ecological)

Organism, often photosynthetic protist, that generates organic matter from CO₂.

Fungus (plural Fungi)

Heterotrophic eukaryote with cell walls of chitin; absorbs nutrients.

Hypha (plural Hyphae)

Filamentous fungal cell forming body of multicellular fungi.

Mycelium

Interwoven mass of hyphae; main nutrient-absorbing structure of a fungus.

Chitin

Strong nitrogen-containing polysaccharide in fungal cell walls.

Spore (fungal)

Reproductive cell capable of developing into new fungus; produced sexually or asexually.

Pheromone (fungal)

Chemical signaling molecule guiding fungal mating types toward each other.

Mold

Asexually reproducing fungus forming visible mycelia and spores.

Yeast

Single-celled fungus reproducing by budding or fission.

Zoopagomycete

Fungal group mainly parasitic or commensal on animals, fungi, or protists.

Mucoromycete

Fungal lineage containing fast-growing molds like bread mold; many plant associates.

Ascomycete

‘Sac fungus’ producing spores in asci; includes morels, Penicillium, and ergot fungi.

Basidiomycete

‘Club fungus’ producing basidiospores; includes mushrooms, puffballs, shelf fungi.

Ergotism

Poisoning from alkaloids of Claviceps purpurea on grains; causes severe symptoms.

Psilocybin

Psychedelic compound in some basidiomycete ‘magic mushrooms’.

Decomposer (fungal)

Fungus that breaks down dead organic matter, recycling nutrients.

Mycorrhiza

Mutualistic association between fungus and plant root enhancing nutrient uptake.

Lichen

Symbiotic association of fungus with algae or cyanobacteria.

Pathogen (fungal)

Fungus causing disease in plants or animals.

Mycosis

General term for fungal disease in humans or animals.

Candida albicans

Opportunistic yeast causing thrush and vaginal infections.

Ringworm

Skin infection caused by dermatophyte fungi, often Trichophyton species.

Athlete’s foot

Fungal infection of feet, usually by Trichophyton rubrum.

Penicillium

Ascomycete genus producing antibiotic penicillin.

Lovastatin

Cholesterol-lowering drug naturally produced by oyster mushrooms (basidiomycetes).

Ciclosporin

Immunosuppressant drug produced by the ascomycete Tolypocladium inflatum.

Conservation biology

Scientific field devoted to protecting biodiversity at all levels.

Biodiversity crisis

Current accelerated loss of species and ecosystems due to human activities.

Genetic diversity

Variation of genes within a population or species.

Species diversity

Variety of species in an ecosystem or across the biosphere.

Ecosystem diversity

Variety of ecosystems in a region or on Earth.

Endangered species

Species in imminent danger of extinction across all or most of its range.

Threatened species

Species likely to become endangered in the near future.

Ecosystem service

Process by which natural ecosystems sustain human life, e.g., pollination or water purification.

Habitat fragmentation

Splitting of ecosystems into smaller, isolated pieces, threatening species survival.

Introduced species

Species moved by humans to new regions, often becoming invasive.

Overharvesting

Excessive removal of organisms faster than populations can rebound.

Global change

Planet-wide environmental alterations, including climate change and acid rain.

Minimum viable population (MVP)

Smallest population size at which a species can sustain itself.

Biological magnification

Increase in substance concentration at higher trophic levels of food web.

Pharmaceutical pollutant

Drug compounds entering ecosystems, potentially disrupting organisms, e.g., estrogen.

Greenhouse effect

Natural atmospheric process that traps heat radiated from Earth’s surface.

Greenhouse gas

Gas absorbing infrared radiation; includes CO₂ and CH₄.

Climate change

Long-term alteration of temperature and weather patterns, largely driven by greenhouse gases.

Arctic amplification

Phenomenon where Arctic regions warm faster than global average.

Carbon cycle

Movement of carbon among living organisms, atmosphere, oceans, and geologic reservoirs.

Ocean acidification

Decrease in seawater pH due to absorption of excess atmospheric CO₂.

Acid rain

Precipitation with pH below 5.2 formed from air pollutants like SO₂ and NOx.