#genetics

• Albino — A person or animal presenting the traits of albinism; characterized by the partial or total congenital lack of natural pigment (melanin) in the organism, which causes a very fair skin, white or milky hair, and eyes with pinkish or pale blue irises.
• Alkaptonuria — A rare hereditary disorder of aromatic amino acid metabolism (phenylalanine and tyrosine), inherited in an autosomal recessive pattern, caused by a deficiency of the homogentisate 1,2-dioxygenase enzyme. This congenital structural anomaly leads to the accumulation of homogentisic acid (alkapton) in the body, which is excreted in the urine (turning it black upon exposure to air) and deposits in connective tissues and cartilages, causing ochronosis and severe arthropathies in adulthood.
• Allele — One of the alternative forms or molecular variants of the same gene, structurally located at the same locus on a homologous chromosome. Alleles determine different variations of the same phenotypic trait (such as eye color or blood type), interacting with each other through relations of dominance, recessiveness, codominance, or incomplete dominance within diploid organisms.
• Alleles — 1. The plural form of the feminine noun alelă; the totality of alternative forms of the same gene occupying a specific chromosomal locus. 2. A regional, shortened, or familiar variant for the feminine plural demonstrative pronoun of distance 'acelea' (or 'acele'), used colloquially to indicate objects or persons located at a distance.
• Of the allele — 1. The genitive-dative singular form of the feminine noun alelă, used to express possession or attribution of a genetic trait specific to a certain variant of a gene. 2. A regional, popular, or shortened form for the oblique cases of the feminine plural demonstrative pronoun of distance 'acelei' (or 'acelor'), used colloquially in possessive structures.
• The alleles — The definite articulate plural form of the feminine noun alelă; it specifically and directly defines the alternative variants of the same gene occupying a homologous chromosomal locus, viewed as clearly defined objects of study within a diploid organism or a biological population.
• Allelism — The state, property, or biological phenomenon whereby a gene possesses multiple alternative forms or mutant variants (alleles) occupying the same locus on homologous chromosomes. Structurally, this concept underscores genetic diversity within a population, analyzed in Mendelian inheritance studies to explain the functional interactions between phenotypic traits transmitted to offspring.
• Allelogamy — A biological phenomenon or mode of reproduction found in plants, consisting of cross-pollination between different individuals belonging to the same species; reciprocal fertilization. Structurally, allelogamy ensures the maintenance of heterozygosity and genetic recombination, being a crucial evolutionary mechanism that enhances the viability and adaptability of offspring compared to self-pollination.
• Allelo-generating — Determining, stimulating, or responsible for the formation and development of alternative variants of the same gene (alleles); relating to biochemical or mutagenic factors that induce structural variability at the same chromosomal locus. In molecular studies, the term describes an agent or cellular process capable of altering the original nucleotide sequence, leading to the emergence of new allelomorphic forms.
• Allelogenesis — The evolutionary or biochemical process of formation, emergence, and differentiation of alternative forms of a gene (alleles) within the gene pool of a species. Structurally, allelogenesis occurs through point mutations, gene duplications, or successive molecular recombinations, constituting the primary source of gene polymorphism and variability upon which natural selection acts.
• Allelomorph — 1. One of the alternative forms or molecular variants of the same gene, occupying the same locus on a homologous chromosome and controlling different variations of the same phenotypic trait; an allele. 2. Presenting allelomorphic characteristics, structures, or properties, belonging to a pair of alternative genes that interact through relations of dominance or recessiveness.
• Allelomorphism — The state, quality, or biological phenomenon whereby a gene presents itself in the form of multiple alternative variants (allelomorphs or alleles) capable of occupying the same chromosomal locus. This structural concept underscores genetic variability within populations, explaining how paired genes interact to produce phenotypic diversity.
• Allelomorphism — The state, property, or biological phenomenon whereby a single gene possesses multiple alternative forms or molecular variants (alleles) capable of occupying the same chromosomal locus. In population genetics, this structural mechanism represents the central pillar of gene polymorphism, determining the complex ways in which paired genes interact through dominance, recessiveness, or codominance to generate the diversity of hereditary traits.
• Allocarpy — The formation of fruits as a result of cross-pollination (allogamy), a structural biological process through which a flower's ovule is fertilized by pollen coming from a different flower of the same species. This phenomenon guarantees high genetic diversity and increased viability of the resulting seeds.
• Allocyclies — An atypical mitotic or meiotic behavior of certain chromosomes or chromosomal segments (especially heterochromatin), structurally characterized by a desynchronized rhythm of condensation and replication compared to the rest of the chromosomal complement in the nucleus; it can be positive (precocious condensation) or negative (delayed condensation).
• Allochronic — Occurring or developing at different times or during distinct geological eras; relating to organisms, species, or biological processes that are temporally isolated, thereby preventing hybridization or ecological overlap. In evolutionary genetics, the concept describes a structural mechanism of speciation whereby populations become reproductively isolated because their mating or activity periods do not coincide in time.
• Allogamous — A term describing a plant organism or a species that reproduces exclusively or predominantly through cross-fertilization (allogamy), meaning the union of gametes originating from different individuals. In a structural sense, allogamous plants have developed complex adaptive morphological and physiological mechanisms (such as self-incompatibility, dioecy, or protandry) to prevent self-pollination and ensure high genetic variability.
• Allogamous — Relating to plants, flowers, or vegetal species: reproducing via cross-pollination, a biological phenomenon where fertilization is achieved using pollen from another flower belonging to either the same individual or a different individual of the same species. This complex genetic mechanism prevents inbreeding, promotes hereditary variability, and enhances the descendants' adaptability to environmental shifts.
• Allogamy — A biological phenomenon and mode of plant reproduction characterized by cross-pollination; the process whereby the ovules of a flower are fertilized by pollen originating from another flower of the same specimen or from a different individual of the same species. Allogamy represents the primary evolutionary engine in the plant kingdom, ensuring a constant flow of new genes and heightened disease resistance.
• Allogony — A biological phenomenon or structural process describing a modification of the genetic formula or structure occurring due to a spontaneous or induced mutation. This variation differentiates the transformed genetic material from that of the ancestral native form, playing an essential role in the study of evolutionary dynamics, cellular adaptability, and the microevolution of living organisms.