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A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z

R

Races (subspecies)
Radiation
[ionizing] [and cancer] [spectrum of electromagnetic radiation]
Radicle
Root portion of the embryo of seed plants. [View]
Radioimmunoassay (RIA)
Radioimmunotherapy
RAF gene
RAG-1 and RAG-2
Recombination Activating Genes
Random assortment of chromosomes in meiosis
Rapamycin
[as immunosuppressant] [as regulator of transgene expression]
RAS gene
Rate of natural increase (r)
RB (retinoblastoma gene)
Reactant
Substance that enters into a chemical reaction.
Reactive oxygen species (ROS)
Recapitulation
Occurrence, in embryonic development, of stages thought to have occurred in the embryonic development of its ancestors. [Discussion]
Receptor editing
Receptor Tyrosine Kinases (RTKs)
Recognition helix
Recombinant DNA
Recombination
[in meiosis] [ in rII locus ] [in T-even bacteriophages] [nodule] [signal sequence (RSS)]
Recommended dietary allowances (RDAs) (table)
Reconsolidation, of memories
Red blood cells
Redox potential
Redox reaction
A chemical reaction in which electrons are transferred from one atom (which is thereby oxidized) to another (which is thereby reduced).
Red Queen hypothesis
Reduction
Process of adding electrons to a substance.
Reductionism
Reflex
[stretch reflex] [withdrawal reflex]
Refractory period
Brief interval following the propagation of an action potential in a neuron or muscle fiber during which it is incapable of propagating a second action potential. [in neurons] [in muscle fibers]
Regeneration
Regulator gene
A gene that encodes a transcription factor and thus controls the expression of other genes.
Relaxin
Releaser
REM (roentgen equivalent man)
Renin
Repetitive DNA
Replication origin
Replicative senescence
Reporter genes
Repressor
[lac repressor] [tryptophan repressor]
Reproduction
[sexual] [asexual]
Reptiles
Resistin
Respiratory burst
Respiratory Syncytial Virus (RSV)
Respiratory system
[human lungs] [their blood supply] [lungs of other vertebrates]
Response element (RE)
A particular DNA sequence which, when bound by a protein specific for it, turns its associated gene(s) on (or off). Many response elements bind to a complex of a hormone with its protein receptor. [steroid response elements] [response element of a protein hormone]
Resting potential
Restriction endonuclease
An enzyme that cuts DNA molecules at, or close to, a certain sequence of nucleotides. [Discussion]
Restriction fragment length polymorphism (RFLP)]
Reticular formation
Retina, human
Retinal
Retinoblastoma
Retinoids
Retinol (vitamin A)
Retrotransposons
Retrovirus
A virus whose genome consists of RNA which, after infection, is copied by reverse transcriptase into DNA. The human immunodeficiency viruses (HIV) are retroviruses. [life cycle] [as vector in gene therapy]
Reverse transcriptase
An enzyme that catalyzes the synthesis of DNA that is complementary to an RNA template; that is, an RNA-dependent DNA polymerase. [More] [inhibitors]
Rh antigens
Rh disease (hemolytic disease of the newborn)
Rheumatoid arthritis
Rhizobia
Rhizoid
Hairlike structure that serves as a root for bryophytes, fern prothallia, and certain fungi and lichens.
Rhizome
Underground stem. [View]
Rhodopsin
Riboflavin (vitamin B12)
Ribonuclease P (RNase P)
Ribonucleic acid (see RNA)
Ribonucleoprotein
A complex of RNA and protein.
Ribose
Ribosome
[structure] [in protein synthesis] [rRNA genes]
Riboswitches
[and gene transcription] [and mRNA translation]
Ribozyme
[general discussion] [synthetic]
Ribulose bisphosphate carboxylase oxygenase (RUBISCO)
[in photosynthesis] [genes] [and photorespiration]
Rickets
Rickettsias
Rifampin
Risk, relative
Ritalin
Rituximab
RNA
Ribonucleic acid. A polymer of ribonucleotides.
[messenger RNA (mRNA)] [ribosomal RNA (rRNA)] [transfer RNA (tRNA)] [small nuclear (snRNA)] [small nucleolar RNA (snoRNA)] [guide RNA (gRNA)] [antisense RNA] [small interfering RNA (siRNA)] [microRNAs (miRNAs)] [tmRNA] [long noncoding RNA (lncRNA)] [rRNA genes]
RNA editing
RNA interference (RNAi)
RNA polymerase
[types in eukaryotes]
RNA thermosensors
RNA World
Robertsonian fusions
Rods of human retina
Root pressure
Roots
ROS (reactive oxygen species)
Rotifers, bdelloid
Rough endoplasmic reticulum (RER)
Rous sarcoma virus (RSV)
r-strategists
RUBISCO
see Ribulose bisphosphate carboxylase oxygenase
RU-486
A progesterone antagonist used to prevent or terminate pregnancy. Also called mifepristone. [More] [still more]
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