#cell

• From the egg / From the very beginning — A Latin phrase derived from Horace's writings, meaning literally 'from the egg'. In embryology and developmental toxicology, it refers to analyzing a biological process, cellular mechanism, or the action of a teratogenic agent (malformation-inducing toxin) traced right from the egg-cell (zygote) stage or from the moment of fertilization to fully map fetal development disruptions.
• Aberrative — Characterized by aberration; generating deviations, anomalies, or distortions relative to a biological, physical, or logical norm. In optics, it describes a refractive medium or lens that introduces phase or spherical distortions into the light beam. In biology, it refers to mutagenic factors or processes that cause abnormal structural changes in the genetic material.
• Abiotrophy — A biological phenomenon or state characterized by the gradual loss of vitality, diminution of physiological resistance, and progressive degeneration of certain cells, tissues, or organs. This process of early degradation or functional decline is determined by internal, constitutional, or genetic factors, manifesting in the absence of obvious external aggressions.
• Abjudicated — That has been revoked, cancelled, or withdrawn from someone's possession by a court ruling; (about assets, titles, or rights) legally confiscated and assigned, as appropriate, to another person or returned to the public domain. The term qualifies the legal status of an object or prerogative after an abjudication action is finalized.
• Abort — An emergency command, action, or procedure used in computer science, programming, and aerospace technology to forcibly and immediately terminate a process, code execution, software application, or operational mission before its natural completion; (in medicine, literary) a rare term borrowed from English or Latin used as a synonym for abortion or the premature halt of an embryo's development or a pathological process.
• Acanthocyte — A pathologically altered erythrocyte (red blood cell) characterized by an abnormal spherical or star-like shape, displaying multiple rigid, sharp cytoplasmic protrusions (spicules) of irregular length and distribution across its membrane. This morphological change (acanthocytosis) is caused by membrane lipid abnormalities and is encountered in severe conditions such as abetalipoproteinemia, advanced liver diseases, or neuroacanthocytosis.
• Acanthoid — A descriptive term used in biological and medical sciences as an adjective to define an organ, outgrowth, cellular structure, or anatomical element that has the appearance, shape, or characteristics of a spine or thorn. In human and comparative anatomy, it is occasionally used to describe the sharp profile of certain bony apophyses or the shape of membrane spicules found in specific pathological tissue modifications.
• Acariobiont — An organism or cellular biological unit structurally lacking a well-defined, individualized cell nucleus. The term is used synonymously with acariote and serves in fundamental biology to describe primitive life forms or cells in early evolutionary stages where genetic material (DNA or RNA) is not enclosed by a nuclear membrane but dispersed directly within the cytoplasm.
• Acariote — Lacking an individualized, structured cell nucleus, or possessing no nuclear membrane to enclose the genetic material. As a noun, the term designates an anucleated cell (such as mature mammalian erythrocytes) or a primitive biological entity (such as viruses) that lacks a complete cellular structure or a proper nuclear apparatus.
• Acroconidium — An asexual spore (conidium) formed exclusively at the tip, apex, or extremity of a specialized hypha (conidiophore) or a conidiogenous cell, essential for fungal dissemination.
• Acrogenesis — A physiological and structural process of formation, differentiation, or development of plant organs or tissues localized exclusively at the tip or upper extremity of an axis.
• Achromatic lens — The feminine form of the term achromat; describes a lens or optical structure capable of transmitting light without breaking it down into component colors at the edges. In medicine, it refers to a female individual affected by total achromatopsia or, in biology, to cells or tissues that do not bind standard histological dyes.
• Achromatin — The fundamental substance within the nucleus of a living cell, composed mainly of nucleic acids and proteins, characterized by its inability to bind basic histological dyes during laboratory techniques, remaining transparent; it forms the structural support for chromatin during cell division.
• Achromatocyte — A pathologically degraded erythrocyte that has completely lost its hemoglobin content, appearing under the microscope as a pale, discolored, or empty cellular structure; a residual red blood cell (erythrocyte ghost) resulting from a severe hemolytic process or mechanical membrane trauma.
• Achromatophilic — Showing no affinity for standard histological or biological stains, remaining colorless or binding pigments with great difficulty during laboratory techniques. The term describes cellular structures, tissues, or microorganisms exhibiting natural resistance to routine histochemical staining.
• Achromatophilia — The property or characteristic of certain cells, tissues, or microscopic anatomical structures to be achromatophilic, displaying a total resistance or complete lack of affinity toward standard biological stains. In laboratory techniques, this structural biochemical condition prevents pigment fixation, leaving samples colorless after exposure to reagents.
• Achromatopsic — Suffering from achromatopsia; characterized by the total inability to perceive and distinguish the colors of the visible spectrum, with the world being perceived exclusively in shades of gray, white, and black. As a noun, it designates a male individual diagnosed with this rare congenital condition, caused by a severe structural dysfunction of the cone photoreceptor cells in the retina.
• Achromasia — A general term designating the total absence of color or pigments within a structural medium. In medicine, it is synonymous with achromatopsia (total color blindness) or describes cellular and cutaneous depigmentation (lack of melanin); in optics, it defines the perfect correction of chromatic aberrations in a lens system.
• Achromic — Lacking color, discolored, or completely devoid of natural pigments; describing a cellular structure, plant tissue, or microscopic organism presenting a native transparency or chromatic neutrality.
• Chromocenter — A microscopic nuclear structure formed by the fusion or aggregation of the pericentromeric heterochromatic regions (centromeres) of multiple chromosomes during cellular interphase. This dense structural formation, frequently observed within the salivary glands of certain insects (such as the polytene chromosomes of Drosophila), appears under the microscope as an intensely stainable central mass from which the euchromatic chromosomal arms radiate, lacking direct transcriptional activity in that zone.