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A group of bacteria capable of oxidative production of acetic acid from ethanol; particular cultures can contain several species.

Staining that identifies organisms or material retaining dye after an acid-containing decolorization step. The property reflects cell-envelope chemistry; a positive stain alone does not identify every species or demonstrate viability.

Author of comparative research on human and rat pancreatic beta cells. The study distinguished differences in glucose transporter expression from glucokinase expression, helping specify which parts of glucose sensing vary between species.^[ref]

Generation of new neurons in the adult hippocampal dentate region. Whether it mediates a particular drug effect depends on species, age, task and intervention; a rodent dependency does not prove a universal human clinical mechanism.

The Afro-Asiatic wildcat, Felis lybica, is a wild species of Felis distributed across much of Africa and parts of Asia. The Cat Specialist Group distinguishes it from the European wildcat, Felis silvestris, and the domestic cat, Felis catus. Some older work treated these regional wildcats as subspecies of a more broadly defined Felis silvestris.^[ref]

Its relationship to domestication has been investigated genetically. The 2007 comparison of domestic and wild cats found close clustering of domestic samples with sampled Near Eastern wildcats, rather than with every wildcat population equally. In that paper, the relevant lineage was named within the older subspecies scheme.^[ref]

This supports a particular ancestry relationship in the sample; it does not make a present-day Afro-Asiatic wildcat simply a lost pet. A feral cat is a domestic-lineage animal living independently of direct care. Current behavior and genetic ancestry should therefore be recorded separately when studying encounters or hybridization between the populations.

Evolution of distinct species during geographic separation. Persistence of isolation after renewed contact is a further test.

polyploidy combining chromosome complements derived from different species.

Researcher in vertebrate development. Attardi and collaborators investigated neuromesodermal progenitors as a source of spinal-cord cells, connecting a conserved developmental population with species differences in growth dynamics.^[ref]

Annelise Sahin coauthored research on Saccharomyces cerevisiae.^[ref]

Saccharomyces cerevisiae is a particular species of yeast, used in baking, brewing and laboratory research. During ordinary vegetative growth it reproduces by budding: a smaller daughter grows from the mother before separation. Laboratory strains can be maintained as either haploid or diploid biological cells. This makes it possible to investigate genes in a single eukaryote, then use controlled crosses and meiosis to connect a genotype to a phenotype. See Burgess, Powers and Mell, Budding Yeast Saccharomyces cerevisiae as a Model Genetic Organism (2017), pp. 1–2.

An anthelmintic is a substance acting against parasitic worms. Its effect depends on parasite species, developmental stage and drug exposure. Killing an intestinal adult and acting on a tissue larva are therefore different pharmacological tasks.

An apple is the pome produced by a plant of Malus, a taxonomic genus in Rosaceae. The name also commonly refers to the cultivated tree. An apple's seed-bearing core develops from fused carpels, while surrounding floral tissues contribute to its fleshy edible structure. This is an accessory fruit, so identifying the entire flesh with the ovary alone misses part of its development.^{[ref] [ref]}

A crosswise cut exposes the seed chambers and the firmer tissue around them. A lengthwise cut connects that core with the stalk at one end and persistent floral parts at the other. Comparing an apple with a peach is instructive: the peach has a single conspicuous stone surrounding its seed, whereas an apple has several chambers formed by fused carpels.

The taxonomic genus includes trees cultivated for edible fruits and ornamental crabapples. A cultivar is a selected cultivated form, rather than an automatic synonym for a separate species. Differences in fruit size, color and texture can therefore occur within the cultivated material to which the everyday word apple refers.^[ref]

Aspidoscelis is a taxonomic genus of whiptail lizards in Teiidae. It contains both sexually reproducing species and all-female lineages that reproduce by parthenogenesis. This variation makes a closely related set of animals useful for studying how reproduction and chromosome organization interact.^[ref]

In a 2011 experiment, researchers crossed a triploid parthenogenetic female lineage with males of a sexually reproducing lineage. The resulting four-copy hybrid offspring were checked with molecular and chromosome measurements. Some female offspring themselves reproduced by parthenogenesis, establishing laboratory lineages able to reproduce without repeating the original cross.^[ref]

A chromosome-set calculation clarifies the change: an unreduced egg carrying three sets can combine with a sperm carrying one set to make a four-set offspring, $3n+n=4n$. This is tetraploidy, rather than merely four copies of one selected gene. Producing one viable hybrid is also different from demonstrating that its descendants can reproduce. The experiment tested both steps, linking the immediate effects of a cross to the persistence of a new reproductive lineage.

A fish species with surface and cave populations used in studies of eye development and degeneration.

The extinct wild cattle species Bos primigenius. Its regional disappearance must be distinguished from the history of domestic cattle.

An extinct African hominin genus whose species combine different locomotor and feeding character mosaics.

Bacillus anthracis is a rod-shaped bacterium associated with anthrax. Its life history includes a resistant dormant spore state and metabolically active growing cells. A spore is a survival state of the bacterium, not a separate species or a fungal reproductive structure. ^[ref]

The distinction links environmental persistence with disease ecology. Long-lived spores and actively multiplying cells have different physiological properties, so counting one state is not equivalent to measuring growth of the other. The disease also depends on the route by which exposure reaches susceptible tissue. Recognizing the species, detecting exposure and identifying an established infection are therefore separate biological questions.

Bacillus megaterium is the historical species name used for strain KM in the lysozyme wall-removal experiment.

A bacterial species that is a natural host of Bacillus virus phi29. The host identity matters when distinguishing that bacteriophage from unrelated Escherichia coli bacteriophages.

A bacterial strain is a maintained lineage of bacteria descended from a particular isolation in pure culture. It is more specific than a species name. The naming code describes descent from an isolation and subsequent cultures; it does not require every cell forever to retain an identical genome.^[ref]

A concrete example is Pm70, the avian isolate used for the published Pasteurella multocida genome. Naming both the species and the strain identifies the particular material behind a sequence or assay. The 2001 genome paper reported 2,014 predicted coding sequences for Pm70, not a measurement of every member of the species.^[ref]

For an illustrative experiment, compare a parent strain with a derivative in which one candidate gene has been removed, keeping culture conditions comparable. A change in the measured phenotype tests a claim about that derivative under those conditions. It does not make the two cultures different species, nor establish that all other strains would respond identically.

A useful laboratory record therefore connects the strain designation, source culture and any deliberate genetic changes. Otherwise two reports can use the same species name while testing materially different biological preparations.

The Bengalese finch is a domesticated songbird derived from the white-rumped munia, Lonchura striata. Research papers often designate it Lonchura striata var. domestica. The name identifies a domesticated form, rather than by itself establishing a separate wild species. Its learned birdsong makes it useful for experiments on auditory feedback and behavioral change.^[ref]

In 2007, Evren C. Tumer and Michael S. Brainard tested whether small variations in otherwise stable adult birdsong could support learning. A computerized system monitored the pitch of selected song elements and disrupted auditory feedback for a selected subset of renditions. The birds shifted the targeted pitch to avoid the disruption, while other song features were relatively preserved. Delaying the feedback prevented the adaptive shift in the reported comparison.^[ref]

For an illustrative version of the logic, suppose feedback is disrupted only when one chosen song element falls below a preset pitch. Later singing above that threshold would reduce disruption. The key comparison is the distribution of that element before and after contingent feedback, together with appropriate feedback controls. A shift need not mean the bird acquired an entirely new song; it can reveal adjustment of one feature within a practiced behavior.