Biotechnology and Genetics terms starting with R

186 terms

rest period A physiological condition of viable seed s, buds or bulbs that prevents growth even in the presence of otherwise favourable environmental conditions.
restitution nucleus A single nucleus arising from a failure of nuclear division, either during meiosis, in which a gamete is formed with the unreduced chromosome number; or…
restriction endonuclease A class of enzymes that cut DNA after recognizing a specific sequence. The three types of restriction endonuclease are: I.
Restriction endonuclease (enzyme) A class of endonucleases that cleaves DNA after recognizing a specific sequence, such as BamH1 (GGATCC), EcoRI (GAATTC), and HindIII (AAGCTT). Type I.
restriction enzyme Synonym of restriction endonuclease.
Restriction enzyme, endonuclease A protein that recognizes specific, short nucleotide sequences and cuts DNA at those sites.
restriction enzymes Enzymes that recognize a specific sequence of double-stranded DNA and cut the DNA at that site.
restriction exonuclease A class of enzymes that degrade DNA or RNA, starting from either the 5'- or the 3'-end.
restriction fragment A shortened DNA molecule generated by the cleavage of a larger molecule by one or more restriction endonucleases.
restriction fragment length polymorphism (Abbreviation: RFLP). A class of genetic marker based on the detection of variation in the length of restriction fragments generated when DNA is treated…
Restriction fragment length polymorphism (RFLP) Differences in nucleotide sequence between alleles at a chromosomal locus result in restriction fragments of varying lengths detected by Southern analysis.
Restriction map See Mapping.
restriction site Synonym of recognition site.
Restriction-enzyme cutting site A specific nucleotide sequence of DNA at which a particular restriction enzyme cuts the DNA. Some sites occur frequently in DNA (e.g.
reticulocyte A slightly immature red blood cell.
Retinoic acid (REH-tih-NOH-ik A-sid) A form of vitamin A that is made by the body, and can also be made in the laboratory.
retro-element Any of the integrated retrovirus es or the transposable elements that resemble them.
retroposon A transposable element that moves via reverse transcription but lacks the long terminal repeat sequences necessary for autonomous transposition.
Retroviral infection The presence of retroviral vectors, such as some viruses, which use their recombinant DNA to insert their genetic material into the chromosomes of the…
retroviral vectors Gene transfer systems based on viruses that have RNA as their genetic material.
retrovirus (REH-troh-VY-rus) A type of virus that has RNA instead of DNA as its genetic material.
reversal transfer Transfer of a culture from a callus-supporting medium to a shoot-inducing medium.
Reverse genetics Using linkage analysis and polymorphic markers to isolate a disease gene in the absence of a known metabolic defect, then using the DNA sequence of the…
reverse mutation See: reversion.
Reverse transcriptase An enzyme that uses an RNA molecule as a template for the synthesis of a complementary DNA strand. Synonym: RNA -dependent DNA polymerase.
Reverse transcriptase (RNA-dependent DNA polymerase) An enzyme isolated from retrovirus-infected cells that synthesizes a complementary (c)DNA strand from an RNA template.
reverse transcription (ree-VERS tran-SKRIP-shun) In biology, the process in cells by which an enzyme makes a copy of DNA from RNA.
reversion Restitution of a mutant gene to the wild-type condition, or at least to a form that gives the wild-type phenotype; more generally, the appearance of a…
RF Abbreviation for replicative form.
RFLP See Restriction\-fragment\-length polymorphism.
RH Abbreviation for recombinant human.
rhizobacterium A micro-organism whose natural habitat is near, on, or in, plant roots.
Rhizobia Bacteria in a symbiotic relationship with leguminous plants that results in nitrogen fixation. See Nitrogen fixation.
Rhizobium (pl.: Rhizobia) Prokaryotic species which are able to establish a symbiotic relationship with leguminous plants, as a result of which elemental nitrogen…
Rhizosphere The soils region on and around plant roots.
Ri plasmid A class of large conjugative plasmid s found in the soil bacterium Agrobacterium rhizogenes , which can infect certain plants and cause hairy root disease.
RIA Abbreviation for radioimmunoassay.
ribonuclease (Abbreviation: RNA se). Any enzyme that catalyses the hydrolysis of RNA.
ribonucleic acid (RY-boh-noo-KLAY-ik A-sid) One of the two types of nucleic acids found in all cells.
Ribonucleic acid (RNA) A chemical similar to a single strand of DNA. In RNA, the letter U, which stands for uracil, is substituted for T in the genetic code.
ribonucleoside See: nucleoside.
Ribonucleotide See: nucleotide.
Ribose A monosaccharide found in all ribonucleosides, ribonucleotides and RNA. Its close analogue, 2-deoxyribose, is similarly found in all deoxyribonucleosides…
ribosomal binding site A sequence of nucleotides near the 5' end of a bacterial mRNA molecule that facilitates the binding of the mRNA to the small ribosomal sub-unit.
ribosomal DNA The coding locus for ribosomal RNA. This is generally a large and complex locus, typically composed of a large number of repeat units, separated from one…
ribosomal RNA (Abbreviation: rRNA). The RNA molecules that are essential structural and functional components of ribosomes, where protein synthesis occurs.
Ribosomal RNA (rRNA) The RNA component of the ribosome. (See RNA.)
Ribosome Cellular organelle that is the site of protein synthesis during translation. See Organelle, Translation.
Ribosome-binding site The region of an mRNA molecule that binds the ribosome to initiate translation.
ribosome-inactivating protein (Abbreviation: RIP). A class of plant proteins that inhibit normal ribosome function, and are thus highly toxic.
Ribosomes Small cellular components composed of specialized ribosomal RNA and protein; site of protein synthesis. See also: RNA
Ribozyme See Catalytic RNA.
ribulose A keto-pentose sugar (C5H11O5) involved in the carbon dioxide fixation pathway of photosynthesis.
ribulose biphosphate (Abbreviation: RuBP). A five-carbon sugar combined with carbon dioxide to form a six-carbon intermediate in the first stage of the dark reaction of…
rinderpest Cattle plague; a viral infection of cattle, sheep and goats.
RIP The procedures used to unbundle email collections into individual emails during the e-discovery process while preserving authenticity and ownership.
Risk The possibility of loss; the uncertainty of future returns.
risk analysis A process consisting of three components: risk assessment, risk management and risk communication performed to understand the nature of unwanted, negative…
risk assessment a scientifically based process consisting of the following steps: i) hazard identification; ii) hazard characterization; iii) exposure assessment; and iv)…
risk communication The interactive exchange of information and opinions throughout the risk analysis process concerning hazards and risks, risk-related factors and risk…
risk management The process, distinct from risk assessment, of weighing policy alternatives, in consultation with all interested parties, considering risk assessment and…
RNA One of the two types of nucleic acids found in all cells. In the cell, RNA is made from DNA (the other type of nucleic acid), and proteins are made from…
RNA (Ribonucleic acid) An organic acid composed of re- peating nucleotide units of adenine, guanine, cytosine, and uracil, whose ribose components are linked by phosphodiester…
RNA editing Post-transcriptional processes that alter the information encoded in RNA s.
RNA polymerase Transcribes RNA from a DNA template. (See Polymerase, RNA.)
RNA-dependent DNA polymerase See: reverse transcriptase.
RNAase Abbreviation for ribonuclease.
RNase Abbreviation for ribonuclease.
rol genes A family of genes, present on the Ri plasmid of Agrobacterium rhizogenes, that when transferred to a plant upon infection by the bacterium, induce…
root To trap a target in place/stuck using a "root" type spell such as Entangling Roots.
root apex The apical meristem of a root; very similar to the shoot apical meristem in that it forms the three meristematic areas: the protoderm (develops into the…
root cap A mass of reinforced cells covering and protecting the apical meristem of a root.
root culture The culture of isolated apical or lateral root tips to produce in vitro root systems with indeterminate growth habits.
root cutting Cutting made from sections of roots alone.
root hairs Outgrowths from epidermal cell walls of the root, specialized for water and nutrient absorption.
root nodule A small round mass of cells attached to the roots of leguminous plants, containing symbiotic nitrogen-fixing bacteroids, particularly Rhizobium spp.
root tuber Thickened root that stores carbohydrates.
Root zone The volume of soil or growing medium containing the roots of a plant. In soil science, the depth of the soil profile in which roots are normally found.
rootstock The trunk or root material to which buds or scions are inserted in grafting. See: stock.
rotary shaker Rotating apparatus with a platform on which liquid media or cultures can be continuously shaken.
Roundup-readyä Describing transgenic crop varieties that carry the bacterial gene which detoxifies the herbicide glyphosate, thereby making them resistant to its…
rRNA See Ribosomal RNA.
RuBP Abbreviation for ribulose biphosphate.
ruminant Animal having a rumen - a large digestive sac in which fibrous plant material is fermented by commensal microbes, prior to its digestion in a "true"…
Runner Typically said "runner-runner" to describe a hand that was made only by catching the correct cards on both the turn and the river.
rust A generic descriptor for various serious fungal plant pathogens, which infect the leaves and stems of crops.