Bio 1400 Exam II: Prokaryotes, Protists, Plants, and Fungi

Vocabulary practice flashcards covering prokaryotes, protists, plants, and fungi for the Bio 1400 Exam II Practice Sheet.

Prokaryotic Cell Shapes

The three primary morphological forms found in prokaryotes: spherical (coccus), rod-shaped (bacillus), and spiral or wavy (spirillum).

Coccus

A spherical or round prokaryotic cell shape.

Bacillus

A rod-shaped bacterial or prokaryotic cell.

Spirillum

A spiral or wavy prokaryotic cell shape.

Gram-Positive Bacteria

Bacteria that possess simpler cell walls containing a large amount of peptidoglycan, which retain crystal violet stain and appear purple.

Gram-Negative Bacteria

Bacteria with structurally more complex cell walls containing less peptidoglycan and an outer membrane with lipopolysaccharides; they stain pink/red and are more resistant to antibiotics.

Endospore

A durable, dormant cell structure produced by certain bacteria to withstand harsh conditions such as heat and desiccation.

Plasmid

A small, circular, self-replicating DNA molecule found in prokaryotes that is separate from the main bacterial chromosome.

Nucleoid

The non-membrane-enclosed region in a prokaryotic cell where the single circular chromosome is concentrated.

Transformation

The process by which a prokaryotic cell takes up and incorporates foreign DNA directly from its surrounding environment.

Transduction

The transfer of prokaryotic genes from one host cell to another by bacteriophages (viruses).

Conjugation

The direct transfer of genetic material between two bacterial cells that are temporarily joined via a mating bridge.

Extremophile

An organism, typically within domain Archaea, adapted to live in environmental conditions so severe that few other species can survive.

Halophile

An extremophilic organism that thrives in environments with extremely high salt concentrations.

Thermophile

An extremophilic organism that thrives in very hot environments.

Methanogen

An archaean that uses carbon dioxide to oxidize hydrogen, releasing methane as a waste product in anaerobic environments.

Biofilm

A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation.

Nitrogen Fixation

The conversion of atmospheric nitrogen ($N_2$) into ammonia ($NH_3$), carried out by certain prokaryotes.

Endosymbiosis

A relationship between two species in which one organism lives inside the cell or cells of another organism; responsible for the evolution of mitochondria and plastids.

Mixotroph

An organism capable of combining photosynthetic autotrophy and heterotrophic nutrition depending on environmental conditions.

Euglenozoan

A diverse clade of protists characterized primarily by the presence of a spiral or crystalline rod inside their flagella.

Cuticle

A waxy epidermal coating on aboveground plant parts that minimizes water loss and protects against desiccation.

Xylem

The vascular plant tissue that conducts water and dissolved minerals upward from the roots to the rest of the plant.

Phloem

The vascular plant tissue responsible for transporting sugars and other organic nutrients throughout the plant.

Stoma (plural: stomata)

A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that regulates gas exchange ($CO_2$ and $O_2$) and water vapor loss.

Seed

A plant reproductive structure consisting of an embryo packaged along with a nutrient supply inside a protective coat.

Gymnosperm

A vascular plant that produces seeds that are not enclosed within an ovary or fruit, literally meaning 'naked seed'.

Hyphae

The branching, thread-like filaments that compose the vegetative body (mycelium) of a fungus.

Mycelium

The densely branched network of hyphae forming the vegetative, nutrient-absorbing body of a multicellular fungus.

Lichen

A symbiotic association between a photosynthetic microorganism (such as a green alga or cyanobacterium) and a fungus.

Mycorrhizae

Mutually beneficial symbiotic relationships between fungi and plant roots that enhance the plant's absorption of water and minerals.

Chitin

A strong, flexible polysaccharide that forms the structural component of fungal cell walls.

Haustoria

Specialized hyphae in parasitic or mutualistic fungi that penetrate host tissues to extract or exchange nutrients.

Plasmogamy

The fusion of the cytoplasm of two parent mycelia during the sexual cycle of fungi without the immediate fusion of their nuclei.

Heterokaryon

A fungal mycelium formed after plasmogamy containing two or more genetically distinct, haploid nuclei that coexist without immediately fusing.

Karyogamy

The fusion of two haploid nuclei in a fungal heterokaryon, resulting in the formation of a diploid zygote.