#cellular structure

• 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.
• Agenosome — A cellular organelle or subcellular structure with a specific role in replication or division processes, occasionally described in specialized biological literature regarding the absence or modification of active genetic material. It represents a discrete structural entity used to explain particular mechanisms of cellular differentiation or experimentally induced chromosomal abnormalities.
• Amphithecium — The outer sterile layer or thalline margin that surrounds and protects the fruiting body (apothecium) of certain lichens; an external cellular layer, distinct from the parathecium, which often contains algal cells and provides structural support as well as mechanical protection against unfavorable environmental factors.
• Antigenic — The feminine form of the adjective 'antigen' or a feminine noun variant used to designate an immune-triggering substance; it describes a molecular, viral, or cellular structure capable of stimulating the immune system to produce specific antibodies.
• Anthoxanthin — A water-soluble plant pigment belonging to the flavonoid class, possessing a white, yellowish, or cream color, present in the cellular vacuoles of many plants, flowers, and fruits (such as cauliflower, onions, or white petals). This structural organic compound modifies its spectral hue depending on the acidity of the medium, becoming intense yellow in the presence of alkaline substances, and plays an essential role in protecting plant tissues against ultraviolet radiation and in cellular oxidation processes.
• Anuclear — Not related to a cellular nucleus or situated outside nuclear structures; a term used in molecular biology to describe phenomena, biochemical processes, or cytoplasmic components that occur independently of the direct control or physical presence of the nucleus.
• Archiochrome — An extremely rare term used in some works on the history of biology or early evolutionary theories to designate a hypothetical primitive biological pigment or the original, ancestral state of coloration of an organism or cellular structure. It represents a structural theoretical concept that attempted to explain the evolution of chromatic systems in nature from simple to complex forms.
• Astrocentre — The central zone, often clear of granules, of the centrosome (cell center), located in the immediate vicinity of the nucleus of a eukaryotic cell during cell division. This structural micro-domain surrounds the centrioles and serves as an organization focal point for mitotic apparatus microtubules, coordinating the spindle formation and the correct migration of chromosomes.
• Autobrecie — A specialized medical term describing a rare form of autonomous structural tissue fragility or a congenital predisposition of cellular elements to undergo spontaneous fracture or rupture without an obvious external traumatic cause.
• Axoneme — A fundamental internal structure, formed by an organized complex of cylindrical microtubules, constituting the central axis and motor skeleton of cilia and flagella in eukaryotic cells. The classical structural configuration follows the '9+2' geometric pattern, composed of nine peripheral microtubule doublets symmetrically arranged around a central pair, interconnected by delicate dynein and nexin bridges that facilitate propulsive oscillatory or undulatory movement.