Biology

Crypsis

Cryptomonad

Cryptomonads (Cryptophyta): small flagellate algae with complex plastids

Cryptomonads are mostly unicellular, flagellated algae found in fresh, brackish, and marine waters. Many contain complex chloroplasts with a nucleomorph and can be photosynthetic,

Cryptosporidium

Cryptosporidium: overview, transmission, diagnosis, treatment, and prevention

Cryptozoology

Cryptozoology: study of hidden, unverified, and rediscovered animals

Cryptozoology examines reports and legends of animals whose existence is unproven or disputed, exploring methods, history, notable examples, and the scientific and cultural controv

Ctenophore

Cunnilingus

Cunnilingus: anatomy, practice, history and safety

Cuticle

Cuttlebone

Cyanobacteria

Cycliophora

Cycliophora: tiny commensal animals and their unique phylum

Cycloneuralia

Cyclostome

Cyclostomes: the jawless fishes (lampreys and hagfish)

Cyst

Cyst: definition, structure, common types, causes, diagnosis and treatment

Cytochrome

Cytochrome: hemoproteins that mediate biological electron transfer

Cytogenetics

Cytogenetics: study of chromosomes, karyotypes, and cell division

Cytokine

Cytokinesis

Cytokinin

Cytokinins: plant hormones that regulate growth and development

Cytology

Cytoplasm

Cytoplasmic streaming

Cytoplasmic streaming (protoplasmic streaming)

Cytosine

Cytoskeleton

Cytosol

Cytotoxic T cell

Darwinism

Darwinism: theory, history, and modern meanings

Database of Molecular Motions

Death

Decomposer

Decomposition

Decomposition: Biological and Chemical Breakdown of Organic Matter

Defecation

Defence against predators

Defence against predators: strategies, evolution, and examples

Defensin

Defensin — small antimicrobial peptides in animals and plants

Deinococcus radiodurans

Deinococcus radiodurans — exceptionally radiation‑resistant bacterium

Deinococcus–Thermus

Deinococcus–Thermus: radiation‑resistant and thermophilic bacteria

Demosponge

Demosponge (Class Demospongiae)

Dendrite

Dendrite: structure, function, development, and biological significance

Dendritic cell

Dendritic cell: antigen-presenting sentinels of the immune system

Dendrology

Dental formula

Dental formula: notation and meaning of mammal teeth counts

Dental pulp

Dental pulp: structure, function, development, and clinical importance

Denticle (teeth)

Denticles (tooth serrations): form, function, and significance

Dentin

Dentin: structure, formation, and clinical significance

Dentition

Dentition: types, development, and biological significance

Deomyinae

Deoxyribose

Deoxyribose: the sugar of DNA

Detritivore

Detritus

Detritus: non-living organic particulate matter in ecosystems