Biology

Membrane

Membrane: biological barriers and synthetic films

Membrane protein

Mendelian inheritance

Meninges

Menopause

Menstrual cycle

Recurring physiological cycle in reproductive-age people that prepares the uterus for pregnancy; includes bleeding, ovulation, hormonal regulation, and clinical variations.

Meselson–Stahl experiment

Meselson–Stahl experiment: demonstration of semiconservative DNA replication

Classic 1958 experiment by Meselson and Stahl using isotopic nitrogen and density-gradient centrifugation to show that DNA replication is semiconservative; outlines method, results

Metabolic rate

Metabolism

Metabolism — the cellular chemical networks that sustain life

Metacarpal bones

Metacarpal bones: structure, function, and clinical importance

Metalloprotein

Metalloprotein: proteins containing metal ion cofactors

Metamorphosis

Metamorphosis: Biological transformation from juvenile to adult

Metatarsal bones

Metroid (species)

Microanatomy

Microanatomy: the microscopic structure of tissues and cells

Microbial cyst

Microbial cyst: dormant survival stage in microbes

Microbial mat

Microbiology

Microorganism

Microtubule

Microvillus

Microvillus and Microvilli: structure, function, distribution, and clinical notes

Midge

Midge (small flies in several families)

Mimicry

Mimicry (biological imitation and deception)

Mimicry is the resemblance evolved between organisms or traits that gives an advantage by deception or signaling, common in insects, plants and animals and arising through natural

Mimivirus

Mitochondria

Mitochondria: structure, function, and roles in cellular metabolism

Mitochondrial DNA

Mitochondrial DNA (mtDNA)

Mitosis

Mitosis: process, stages, and biological significance

Mixotroph

Mixotroph — organisms using multiple energy and carbon strategies

Mobile genetic elements

Model organism

Model organism (biological research)

Modern evolutionary synthesis

Molar

Molar (tooth) — structure, function, development, and variation

Molecular biology

Molecular clock

Molecular cloning

Molecular cloning: methods, components, history and applications

Molecular evolution

Molecular evolution: how DNA, RNA and proteins change through time

Mollicutes

Monocyte

Monocyte: circulating precursor immune cells that become macrophages and dendritic cells

Monogenea

Monogenea: ectoparasitic flatworms of fish and other aquatic hosts

Monophyly

Monophyly in Evolutionary Biology: Defining Clades, Paraphyly, and Polyphyly

Monoplacophora

Monoplacophora — limpet-like molluscs: fossil record, anatomy and rediscovery

Moraxella

Moraxella — a genus of Gram-negative bacteria

Moraxellaceae

Moraxellaceae: a family of gram-negative bacteria

Morganucodon

Morganucodon: an early mammaliaform and its role in mammal evolution

Morphogenesis

Morphology

Morphology: the study of form and structure across disciplines

Morphology (biology)

Mosaic (genetics)

Mosaicism (genetics)