Biology Dictionary: O
Search or browse the dictionary for the definition of biology terms starting with the letter “O”.
Dictionary > O
O
- O antigen
- Oar
- Oasthouse urine disease
- Ob
- Obdiplostemonous
- Obelisk
- Obermayers test
- Obesity
- Object
- Objective
- Objectives
- Objects
- Oblate
- Obligate
- Obligate aerobe
- Obligate anaerobe
- Obligate mutualism
- Obligate parasite
- Oblique
- Oblique muscle
- Obliterate
- Obscure
- Observation
- Observer
- Obsolete
- Obstinate
- Obstruction
- Occiput
- Occlusion
- Occult
- Occultation
- Occupations
- Ocean
- Oceanian realm
- Octapeptide
- Octology
- Octoploid
- Octose
- Ocular
- Ocular micrometer
- Oculocutaneous albinism
- Ocyte
- Odd-pinnate
- Odds
- Odontophore
- Odontoprisis
- Oedema
- Oesophagus
- Oestrous Cycle
- Oestrus
- Offensive
- Offset
- Offsets
- Offshoot
- Offspring
- Ohngrens line
- Oil
- Oil retention enema
- Oils
- Ointment bases
- Okazaki fragment
- Old World monkey
- Olecranon
- Oleoresin
- Olfactory
- Olfactory nerve
- Olfactory receptor cells
- Oligohydramnios
- Oligonucleotide
- Oligopeptide
- Oligosaccharide
- Oligospermia
- Ology
- Olympian forehead
- Omega
- Omega-6 fatty acid
- Ominous
- Omission
- Omit
- Omniscient
- Omnivore
- Omnivorous diet
- Oncogene
- Onion
- Online systems
- Ontogenesis
- Ontogeny
- Onych-
- Onychatrophia
- Oocyst
- Oocyte
- Oogenesis
- Oogonium
- Ookinete
- Oospore
- Ootid
- Ooze
- Opacity
- Opaque
- Opaque microscope
- Open circulatory system
- Open Population
- Open system
- Open tuberculosis
- Opera
- Operant conditioning
- Operation
- Operator
- Operator gene
- Operator region
- Operculum
- Operon
- Operon Model
- Ophiuroidea
- Ophthalmomalacia
- Opine
- Opisthaptor
- Opisthomastigote
- Opportunistic
- Opportunistic pathogen
- Oppose
- Opposite
- Opposition
- Opsonin
- Opsonization
- Optical
- Optical density
- Optically active
- Optimal
- Optimum
- Opuntia
- Ora
- Oral
- Oral cavity
- Oral vestibule
- Orange
- Orbicularis oris
- Orbiculated
- Orbit
- Orbital
- Orbits
- Orchestra
- Orchids
- Orcinol
- Orcinol test
- Ord
- Order
- Ordinal
- Ordinate
- Ordination
- Ore
- Orexia
- Organ
- Organ culture
- Organ specificity
- Organ-specific antigen
- Organa oculi accessoria
- Organa sensuum
- Organelle
- Organic
- Organic acid
- Organic catalyst
- Organic chemistry
- Organic compound
- Organic matter
- Organic molecule
- Organic synthesis
- Organism
- Organization
- Organizational affiliation
- Oriental
- Orientation
- Orienting reflex
- Orifice
- Origin
- Origin of replication
- Originals
- Ornithine
- Ornithology
- Oro
- Oropharynx
- Orotic acid
- Orthodox
- Orthogonal
- Orthologous Gene
- Orthology
- Os
- Os multangulum minus
- Os uteri internum
- Oscillation
- Oscilloscope
- Osculum
- Osmoreceptor
- Osmoregulation
- Osmosis
- Osmotic lysis
- Osmotic Potential
- Osmotic pressure
- Osmotolerance
- Osmotrophy
- Ossa digitorum
- Ossa membri superioris
- Osseous tissue
- Ossicles
- Ossicular chain
- Ossification
- Osteichthyes
- Ostempyesis
- Ostentatious
- Osteoblast
- Osteoclast
- Osteocyte
- Osteomalacia
- Osteon
- Osteopetrosis
- Osteoporosis
- Ostia venarum pulmonalium
- Ostium
- Ostrich
- Otary
- Otic
- Otodynia
- Otolith
- Out of Africa model
- Outbreak
- Outbreeding
- Outer membrane
- Outgroup
- Outlet
- Output
- Outwelling
- Ova
- Ovalbumin
- Ovarian cycle
- Ovarian fossa
- Ovary
- Ovate
- Oven dry ton
- Overbank flooding
- Overdominance
- Overgrowth
- Overhang
- Overlap
- Overlapping
- Overlapping genes
- Overlay
- Overshoots
- Overstory
- Overventilation
- Oviduct
- Oviparous
- Ovocyte
- Ovoid
- Ovoviviparous
- Ovulation
- Ovule
- Ovum
- Owe
- Owl
- Ox
- Ox heart
- Oxaloacetate
- Oxic
- Oxidant
- Oxidase
- Oxidation
- Oxidation-fermentation test
- Oxidation-reduction
- Oxidative metabolism
- Oxidative phosphorylation
- Oxidise
- Oxidize
- Oxidizer
- Oxidizing agent
- Oxidoreductase
- Oxy-
- Oxygen
- Oxygen capacity
- Oxygen consumption
- Oxygen Debt
- Oxygen deficit
- Oxygen dependent killing
- Oxygenase
- Oxygenic
- Oxyhemoglobin
- Oxytocin
- Oyster
- Ozochrotia