A

  • Abdomen
  • Abiotic factors
  • Active site
  • Adaptive radiation
  • Adrenal gland
  • Aldosterone
  • Allantois
  • Allopatric speciation
  • Amino acids
  • Amniotes
  • Amphipathic
  • Anaerobic respiration
  • Anaphase 1
  • Anatomy
  • Animal circulatory system
  • Anthropometry
  • Antioxidant
  • Apoptosis
  • Artificial selection
  • ATP synthase
  • Autophagy
  • Autotroph
  • Abdominal cavity
  • Acetic acid
  • Active transport
  • Adenosine triphosphate (ATP)
  • Aerobic respiration
  • Algae
  • Allele
  • Alternation of generations
  • Ammonification
  • Amniotic fluid
  • Anabolism
  • Analogous structure
  • Anaplasia
  • Angiosperm
  • Antecubital fossa
  • Antibody
  • Apical meristem
  • Archae bacteria
  • Asexual reproduction
  • Atrophy
  • Autopsy
  • Auxin
  • Abiogenesis
  • Active immunity
  • Adaptation
  • Adhesion
  • Agonist
  • Alimentary canal
  • Allele frequency
  • Alternative splicing
  • Amnion
  • Amoeba
  • Anaerobic organisms
  • Anaphase
  • Anatomical position
  • Animal cell
  • Anthropod
  • Anticodon
  • Apoplexy
  • Articular cartilage
  • Atavism
  • Autonomic nervous system
  • Autosomes