Biology Dictionary: A
Search or browse the dictionary for the definition of biology terms starting with the letter “A”.
Dictionary > A 
  A
- A Band
 - A chain
 - A layer
 - A posteriori
 - A-v
 - Abdomen
 - Abdominal cavity
 - Abdominal raphe
 - Abdominal reflex
 - Abdominopelvic cavity
 - Abduction
 - Aberrant regeneration
 - Abiogenesis
 - Abiotic
 - Abiotic factor
 - Abiotic Fixation
 - Abiotic resource
 - Abiotic stress
 - Abnormal
 - Abo blood group
 - Abortion
 - Abortive transduction
 - Abscisic acid
 - Abscissa
 - Abscission
 - Absolute fitness
 - Absolute Refractory Period
 - Absorbance
 - Absorption
 - Absorption cell
 - Absorption chromatography
 - Absorption Spectrum
 - Absorptive cells of intestine
 - Abtropfung
 - Abundance
 - Acceptor
 - Accessories
 - Accessory Chromosome
 - Accessory fruit
 - Accessory organs
 - Accessory pigment
 - Accidental host
 - Acclimation
 - Accole forms
 - Accommodation
 - Accommodation of nerve
 - Accommodation reflex
 - Accretions
 - Accumulation
 - Acellular
 - Acetabulum
 - Acetobacter
 - Acetyl Coenzyme A
 - Acetylcholine
 - Achenes
 - Achilles reflex
 - Achlorhydria
 - Achromatic
 - Achromia parasitica
 - Achromotrichia
 - Acid
 - Acid dye
 - Acid indicator
 - Acid Precipitation
 - Acidic
 - Acidophile
 - Acidosis
 - Acinetobacter lwoffii
 - Acoelomate
 - Acorn
 - Acquired
 - Acquired sensitivity
 - Acquired trait
 - Acroarthritis
 - Acrobrachycephaly
 - Acrocentric chromosome
 - Acromegaly
 - Actinopterygian
 - Actinozoa
 - Action potential
 - Activation
 - Activation energy
 - Activator
 - Active agglutination
 - Active centre
 - Active dry yeast
 - Active principle
 - Active site
 - Active transport
 - Actual resource
 - Acute febrile illness
 - Adair-koshland-nemethy-filmer model
 - Adansonian classification
 - Adaptation
 - Adaptive behaviour
 - Adaptive evolution
 - Adaptive radiation
 - Adaptive trait
 - Adaptive zone
 - Adder
 - Additive effect
 - Additive genes
 - Adduction
 - Adductor muscle
 - Adenine
 - Adenine nucleotide
 - Adenofibrosis
 - Adenosine
 - Adenosine diphosphate
 - Adenosine monophosphate
 - Adenosine triphosphate
 - Adfluvial
 - Adhering junction
 - Adhesion
 - Adipocyte
 - Adipose tissue
 - Adjuvant
 - Administration
 - Adrenaline
 - Adsorption
 - Adultery
 - Adventitious bud
 - Adventitious embryony
 - Adventitious root
 - Adverse effects
 - Aeration
 - Aerial
 - Aerial mycelium
 - Aerial Respiration
 - Aerial root
 - Aerobe
 - Aerobic
 - Aerobic bacteria
 - Aerobic process
 - Aerobic respiration
 - Aerosol
 - Aerotolerant
 - Aerotropism
 - Aestivation
 - Aetiolated
 - Aetiology
 - Af
 - Afferent Nerve
 - Afferent neuron
 - Affinity
 - Affinity chromatography
 - Afrotropical realm
 - Agar
 - Agarose
 - Age distribution
 - Age groups
 - Agent
 - Agglutination
 - Agglutinin
 - Agglutinogen
 - Agglutinophilic
 - Aggregate
 - Aggregate fruit
 - Aggregated lymphatic follicles
 - Aggregated lymphatic nodules
 - Aggressin
 - Aggression
 - Agnathan
 - Agonal rhythm
 - Agonist
 - Agonist muscle
 - Agony
 - Agretope
 - Agriculture
 - Ailment
 - Air
 - Air bladder
 - Air cell
 - Air conduction
 - Air Pollution
 - Air pressure
 - Airway
 - Airy disk
 - Akinetes
 - Ala minor
 - Ala orbitalis
 - Alanine
 - Albinism
 - Albino
 - Albumin
 - Alcohol
 - Alcoholic Fermentation
 - Aldohexoses
 - Aldose
 - Aldosterone
 - Aldotriose
 - Algae
 - Algal bloom
 - Algology
 - Aliment
 - Alimentary canal
 - Alimentary glycosuria
 - Aliphatic
 - Aliphatic acids
 - Aliquot
 - Alive
 - Alkadienes
 - Alkaline
 - Alkaline reaction
 - Alkaliphile
 - All-Or-None-Law
 - Allantois
 - Allee effect
 - Allele
 - Allele frequency
 - Allelic exclusion
 - Allelism
 - Allergy
 - Alligator
 - Allogamy
 - Alloimmunity
 - Allometric Growth
 - Allopatric speciation
 - Allopatry
 - Allopolyploidy
 - Allose
 - Allosteric Inhibitors
 - Allotetraploid
 - Alpaca
 - Alpha-helix
 - Alphaproteobacteria
 - Alt
 - Alternative hypothesis
 - Altitude
 - Altrose
 - Alveolalgia
 - Alveolar cell
 - Alveolar duct
 - Alveolar gland
 - Alveolus
 - Amastigote
 - Amaurotic pupil
 - Ambient
 - Ambiguous codon
 - Amelanism
 - Ametaboly
 - Ami
 - Amino acid
 - Amino acid sequence
 - Amino sugar
 - Amitosis
 - Ammonia
 - Ammonification
 - Ammonotelism
 - Amnion
 - Amniote
 - Amniotic Cavity
 - Amniotic fluid
 - Amniotic sac
 - Amoeba
 - Amoebic dysentery
 - Amoebocyte
 - Amoeboid
 - Amoeboid movement
 - Amoebozoa
 - Amorphic mutation
 - Amorphous
 - Amphimixis
 - Amphipathic
 - Amphoteric
 - Amplification
 - Amplifier host
 - Amplitude
 - Amylase
 - Amyloglucosidase
 - Amylopectin
 - Amyloplast
 - Amylose
 - Anabolic pathway
 - Anabolic steroid
 - Anabolism
 - Anaerobe
 - Anaerobic
 - Anaerobic bacteria
 - Anaerobic exercise
 - Anaerobic process
 - Anaerobic respiration
 - Anaesthetic
 - Analgesic
 - Analog
 - Analogous
 - Analogous structures
 - Analogy
 - Anamniote
 - Anaphase
 - Anaphase I
 - Anaphase II
 - Anaphylactic shock
 - Anarthropoda
 - Anastomoses
 - Anastomosis
 - Anatomical
 - Anatomical plane
 - Anatomy
 - Ancestors
 - Anchor
 - Anchorage
 - Anchorage independence
 - Anchorage-independent cell
 - Anchoring junction
 - Ancylostoma
 - Ancylostoma duodenale
 - Androecium
 - Androsterone
 - Anemia
 - Aneuploidy
 - Angiosperm
 - Angiostenosis
 - Angiotensinogen
 - Angiotomy
 - Angulation
 - Angulus sphenoidalis ossis parietalis
 - Anhidrosis
 - Animal
 - Animal cell
 - Animal cell culture
 - Animal Kingdom
 - Animal testing
 - Animals
 - Annealing
 - Annelida
 - Annotated Diagram
 - Annular band
 - Annular lipid
 - Anodal opening contraction
 - Anoderm
 - Anomaly
 - Anomer
 - Anomeric carbon
 - Anoxia
 - Ant
 - Antagonism
 - Antagonist
 - Antagonistic effect
 - Antagonistic Muscle
 - Antarctic realm
 - Antebrachium
 - Antecardium
 - Antecubital fossa
 - Antecubital space
 - Antelope
 - Antemortem thrombus
 - Antenna
 - Antennapedia
 - Anterior extremity
 - Anterior funiculus
 - Anterior primary division
 - Anterolateral
 - Anterolateral system
 - Anther
 - Anther culture
 - Anthozoan
 - Anthropography
 - Anthropoids
 - Anthroponosis
 - Anthropophilia
 - Anthropophilic
 - Antibacterial
 - Antibiotic
 - Antibody
 - Antibody diversity
 - Antibody-forming cell
 - Anticipatory control
 - Anticoagulant
 - Anticodon
 - Antifungal
 - Antifungicide
 - Antigen
 - Antigen-antibody complex
 - Antigenic variation
 - Antigenicity
 - Antimorphic mutation
 - Antioxidants
 - Antisepalous
 - Antiserum
 - Antitoxin
 - Antivitamin
 - Anus
 - Ape
 - Ape hand
 - Apertura mediana ventriculi quarti
 - Apertura thoracis superior
 - Aperture
 - Apetalous
 - Apex of head of fibula
 - Apical bud
 - Apical complex
 - Apical Dominance
 - Apical meristem
 - Apicomplexa
 - Aplanospore
 - Aplasia
 - Apocarpous gynoecium
 - Apocrine gland
 - Apoenzyme
 - Apolar
 - Apomixis
 - Apomorphy
 - Aponeurorrhaphy
 - Apoplast
 - Apoptosis
 - Apparatus
 - Apparent competition
 - Appearance
 - Appendage
 - Appendages
 - Appendages of eye
 - Appendix
 - Apple
 - Application
 - Applied science
 - Appositional growth
 - Approach-approach conflict
 - Apractagnosia
 - Apteria
 - Aquatic
 - Aquatic Respiration
 - Aquatic root
 - Aqueous humor
 - Aqueous solution
 - Arachnology
 - Arboreal
 - Arboreal locomotion
 - Archaea
 - Archaean
 - Archaebacteria
 - Archaellum
 - Archaeplastida
 - Archamoebae
 - Archeocerebellum
 - Archetype
 - Arcus venosus palmaris superficialis
 - Arcus vertebrae
 - Areal cover
 - Areola
 - Areolar gland
 - Areolar tissue
 - Areole
 - Argipressin
 - Aristotle
 - Arm
 - Armadillidiidae
 - Aroma
 - Arrector pili muscles
 - Arrectores pilorum
 - Arrest
 - Arrested tuberculosis
 - Arrhenotoky
 - Arrow poison
 - Artefact
 - Arteriolar sclerosis
 - Arteriole
 - Arthritis
 - Arthrology
 - Arthropod
 - Arthropodology
 - Articular surface
 - Articulata
 - Articulate
 - Articulatio radiocarpea
 - Articulatio tarsi transversa
 - Articulatio trochoidea
 - Articulation
 - Articulationes membri superioris liberi
 - Artificial active immunity
 - Artificial passive immunity
 - Ascaris
 - Ascaris lumbricoides
 - Ascendant
 - Ascidians
 - Asexual reproduction
 - Asian Glossy Starling
 - Asp
 - Asparagus
 - Aspartame
 - Aspartate
 - Aspergillus
 - Aspermia
 - Aspidium
 - Aspirate
 - Ass
 - Assay
 - Assimilation
 - Association
 - Association constant
 - Assumption
 - Asteatosis
 - Aster
 - Asteraceae
 - Asthenic personality disorder
 - Astomia
 - Astragalus
 - Asymmetry
 - Asymptomatic
 - Atavism
 - Atmospherization
 - Atom
 - Atomic mass
 - Atomic weight
 - ATP synthase
 - Atria
 - Atrial natriuretic hormone
 - Atrial syncytium
 - Atriotomy
 - Atrioventricular sulcus
 - Atrioventricular valve
 - Atrium
 - Atrophy
 - Austin disease
 - Australasia realm
 - Autecology
 - Authority figure
 - Autoantigen
 - Autocrine signaling
 - Autogenous
 - Autoimmune disease
 - Autoimmunity
 - Automixis
 - Autonomous
 - Autophagy
 - Autophosphorylation
 - Autophytic Plant
 - Autopolyploidy
 - Autosome
 - Autotomy
 - Autotroph
 - Auxanographic method
 - Auxetic growth
 - Auxin
 - Auxotyping
 - Avascular
 - Aves
 - Avidity
 - Avoidance conditioning
 - Avoidance-avoidance conflict
 - Axenic culture
 - Axial ametropia
 - Axial projection
 - Axils
 - Axis
 - Axon
 - Axon hillock
 - Axon terminal
 - Axoneme