#cell division

• Agamete — An asexual reproductive cell (such as a spore, zoospore, or conidium) capable of directly giving rise to a new living organism without previously fusing with another sexual cell. Its functional structure is specific to lower plants, fungi, and protozoans that utilize alternation of generations in their biological cycle.
• 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.
• Ameiosis — A special type of aberrant or modified cell division in which classic meiosis is not completed or is entirely replaced, resulting in reproductive cells (gametophytes or spores) that retain the unchanged diploid chromosome number of the parent cell (without chromatic reduction). This structural phenomenon is closely linked to the process of apomixis in certain plant species, allowing asexual reproduction through genetically viable seeds.
• Amphitene — A transient stage in the prophase of the first meiotic division, occurring between leptotene and pachytene, synonymous with zygotene, during which homologous chromosomes begin to align and pair up through synapsis. In this structural phase, the chromatid threads often present a characteristic bouquet arrangement, with one end thickened and the other thin during the pairing process.
• Amitotic — Pertaining to amitosis or occurring through amitosis; relating to direct cell division, characterized by the simple cleavage of the nucleus and cytoplasm without the individualization of chromosomes and without the formation of the mitotic apparatus (spindle). This physiological structural mechanism is specific to certain specialized, aged, pathological cells or lower unicellular organisms.
• Anaphase — The third consecutive stage of the cell division process (mitosis or meiosis), structurally characterized by the abrupt separation and simultaneous migration of sister chromatids or homologous chromosomes toward the opposite poles of the cell. This mechanical and biological phenomenon, coordinated by the contraction of the mitotic spindle fibers, guarantees the perfectly equal and exact distribution of the duplicated genetic material to the two future daughter cells.
• Androsporogenesis — The biological, cytological, and physiological process of formation, differentiation, and maturation of androspores inside an androsporangium. This sequence of structural stages involves specialized cell divisions and biochemical rearrangements of the male germ plasm.
• Antimitotic — Preventing, blocking, or halting mitosis (the process of indirect cell division); a chemotherapeutic medication, cytostatic agent (such as vinca alkaloids or taxanes) utilized in the treatment of malignant tumors. In a clinical sense, it acts structurally by disrupting or excessively stabilizing the mitotic spindle, halting the uncontrolled multiplication of cancer cells.
• Antitumor — Preventing, combating, inhibiting, or destroying the development and proliferation of tumors, especially malignant ones; a medication, chemotherapeutic agent, or biological agent used in cancer therapy. These compounds act by blocking abnormal cell division, inducing apoptosis in cancer cells, or halting the angiogenesis necessary for the tumor's nutrition.
• Archiplasm — A historical cytological term proposed by biologist Theodor Boveri to denote the differentiated substance of the cytoplasm surrounding the centrosome, from which the spindle fibers of cell division (the achromatic apparatus) are formed. Although modern molecular biology uses refined concepts like pericentriolar matrix or microtubules, the term remains important in the history of microscopy for describing primordial dynamic cellular structures.