- autacoid
- autoantibody
- autoecious
- autoinhibitor
- autokinetic
- autologous
- aulostomatous
- auto-transplant
- auto-transplantation
- autoinfection
- autolysate
- autolysin
- autopodium
- autospasy
- autotrophy
- auxo-heterotroph
- avascular
- axopetal
- axostyle
- autoparthenogenesis
- autoplasty
- auxesis
- auxocyte
- axoplasm
- backcross
- autophilous
- autoplastic
- autotroph
- auxotroph
- axopodium
- azotobacter
- autoplast
- autoploid
- auxetic
- axenik
- axile
- blastocoel
- blastomere
- blastopore
- blastosphere
- blastula
- blepharoplast
- brachidia
- brucine
- burdon
- cacogenesis
- calcar
- calobiosis
- caenogenesis
- capillitium
- cavitary
- cell-body
- cell-cycle
- cellsap
- centroplasm
- centrosome
- centrum
- cenogenesis
- centriole
- centromere
- chaeta
- centrosphere
- chalone
- chiasmatypy
- chlorella
- chemoautotrophy
- chemotaxis
- chondriosome
- chromomere
- ciliate
- cistron
- clamydospore
- clasper
- chondrioblast
- chondrocranium
- chordate
- chorial
- chromaffin
- chromaffinity
- chromatid
- chromatolysis
- chyliferous
- chromoprotein
- circulatory system
- circumvascular
- cirrate
- cisterna
- clamydate
- clamydosporic
- clasmatocyte
- clava
- coadaptation
- coadunate
- clitellum
- coccolith
- cocosphere
- codominance
- coelarium
- coelomate
- coenospecies