Biology
Articles about living organisms, life processes and biological research.
Anaerobic organism
Anaerobic respiration
Anapsid
Anatomical terms of location
Anatomy
Aneuploidy
Anfinsen's dogma
Anfinsen's dogma: the sequence-driven view of protein folding and its limits
Anguilloidei
Anguilloidei (suborder of eels)
Animal colour
Animal colouration: causes, functions, and evolutionary significance
Animal testing
Annelid
Annelid (segmented worm)
Anoxia
Antenna (biology)
Antenna (biology): sensory appendages of arthropods
Anthocyanin
Anthozoa
Antibody
Antigen
Antigen: definition, types, immune role and clinical importance
Anus
Apicomplexa
Apocrita
Apocrita: the narrow-waisted suborder of Hymenoptera
Apomixis
Apomorphy
Apomorphy (biology): derived traits and their role in phylogeny
Apoplexy
Apoptosis
Appendage
Appendage (anatomy): external projections of animal bodies
Appendix (anatomy)
Appendix (anatomy): structure, function, evolution and clinical importance
Aquatic
Aquatic: organisms, habitats, and key characteristics
Aquatic locomotion
Aquatic locomotion: principles, modes, and evolutionary context
Aquificaceae
Aquificaceae: thermophilic bacteria of hot springs and hydrothermal systems
Aquificae
Aquificae: Thermophilic, Chemolithoautotrophic Bacteria of Hot Environments
Arboreal
Archamoebae
Armillaria gallica
Arrector pili
Artificial insemination
Artificial life
Artificial selection
Ascomycota
Ascomycota (sac fungi): diversity, biology and human relevance
Asepsis
Asepsis: principles, methods, and clinical importance
Asexual reproduction
Aspergillus
Aspergillus: biology, ecology, and significance of a widespread fungal genus
Aspergillus flavus
Aspergillus flavus: biology, health risks, and agricultural impact
Asphyxia
Assimilation (biology)
Astrocytoma
ATP synthase
Atrial-natriuretic peptide
Atrial natriuretic peptide: heart-derived hormone that regulates blood volume and sodium