Biology
Articles about living organisms, life processes and biological research.
Abdomen
Acetobacter
Acetobacter: aerobic bacteria that oxidize alcohol to acetic acid
Acetylcholinesterase
Acidophile
Acidophile: organisms that thrive in highly acidic environments
Acoelomorpha
Actinobacteria
Active transport
Active transport: moving substances across membranes against gradients
Adaptation
Adaptive immune system
Adaptive radiation
Adelobasileus
Adelobasileus — an early mammaliaform from the Late Triassic
Adenosine triphosphate
Adenosine triphosphate (ATP) — the cellular energy carrier
Adipocyte
Adipocyte: structure, types, functions and clinical significance
Adipose tissue
Adrenal gland
Aerobic
Aerobic organism
Aestivation
Agar plate
Agaricomycetes
Ageing
Ageing: biological mechanisms, evolutionary explanations, and societal effects
A clear overview of ageing (senescence): its biological basis, evolutionary theories, population patterns, medical relevance, and distinctions between ageing, disease, and non‑agei
Agnatha
Albinism
Algae
Algae: diversity, ecology, and human uses
Algal bloom
Alicyclobacillaceae
Alimentary canal
Alimentary canal (digestive tract)
Alkaliphile
Allele
Allele frequency
Allotheria
Alpha helix
Alpha helix: structure, bonding, and biological roles
Alternation of generations
Alternative splicing
Alternative splicing: how one gene yields multiple mRNA and protein isoforms
Altricial
Alveolate
Alveolus
Amanita
Amanita: overview of the mushroom genus, identification, and medical importance
Ammonite
Amniotic sac
Amoeba
Amoeboid movement
Amoeboid movement: cell crawling driven by pseudopodia and cytoskeletal dynamics
Amoebozoa
Amygdala
Amylase
Amyloplast
Amyloplast — the starch‑storing plastid in plants