Biotechnology and Genetics — page 34 of 40

3,925 terms including subtopics (0 terms filed directly here)

Subtopics

Biotechnology and Genetics terms

  1. Selective breeding Making deliberate crosses or matings of organisms so the offspring will have a desired characteristic derived from one of the parents.
  2. self-incompatibility In plants, the inability of the pollen to fertilize ovules (female gametes) of the same plant.
  3. Self-pollination Pollen of one plant is transferred to the female part of the same plant or another plant with the same genetic makeup.
  4. self-replicating elements Extrachromosomal DNA elements that have origins of replication for the initiation of their own DNA synthesis.
  5. self-sterility Synonym of self-incompatibility.
  6. SEM Abbreviation for scanning electron microscope.
  7. semen sexing Synonym of sperm sexing.
  8. semi-conservative replication During DNA duplication, each strand of a parent DNA molecule acts as a template for the synthesis of a new complementary strand.
  9. semi-continuous culture Cells in an actively dividing state which are maintained in culture by periodically draining off the medium and replenishing it with fresh medium.
  10. semi-permeable membrane A natural or synthetic material which selectively allows the passage of certain ions or molecules.
  11. semi-sterility The condition of partial fertility. Often associated with chromosomal aberrations or the result of mutagenesis.
  12. Semiconservative replication During DNA duplication, each strand of a parent DNA molecule is a template for the synthesis of its new complementary strand.
  13. senescence A late stage in the development of multicellular organisms, during which irreversible loss of function and degradation of biological components occur.
  14. sense RNA The RNA transcript of the coding strand DNA (often represented as the (+)-strand). Opposite: antisense RNA.
  15. Sensitivity When referring to a medical test, sensitivity refers to the percentage of people who test positive for a specific disease among a group of people who have…
  16. sepsis (SEP-sis) The presence of bacteria or their toxins in the blood or tissues.
  17. septate (SEP-tate) An organ or structure that is divided into compartments.
  18. septum A dividing wall or partition, which splits a structure into separate cells or compartments.
  19. sequence The linear order of nucleotides along a DNA or RNA molecule, and the process of obtaining this.
  20. Sequence assembly A process whereby the order of multiple sequenced DNA fragments is determined.
  21. sequence characterized amplified region (Abbreviation: SCAR). A molecular marker obtained by the conversion to a sequence-tagged site of a single random amplified polymorphic DNA product.
  22. sequence divergence The percent difference in the nucleotide sequence between related nucleic acid sequences, or in the amino acid sequence in a comparison between related…
  23. Sequence hypothesis Francis Crick's seminal concept that genetic information exists as a linear DNA code; DNA and protein sequence are colinear.
  24. Sequence tagged site (STS) A unique (single-copy) DNA sequence used as a mapping landmark on a chromosome.
  25. sequence tandem repeat (Abbreviation: STR). See: tandem repeat.
  26. sequence-tagged site (Abbreviation: STS). Short unique DNA sequence (200-500 bp long) that can be amplified by PCR and is thus tagged to the site on the chromosome from which…
  27. Sequencing Determination of the order of nucleotides (base sequences) in a DNA or RNA molecule or the order of amino acids in a protein.
  28. Sequencing technology The instrumentation and procedures used to determine the order of nucleotides in DNA.
  29. serial division Splitting of excised shoot-tip material growing in vitro, in order to induce the development of greater numbers of plantlets.
  30. serial float culture A technique whereby immature anthers are floated on a liquid medium, and continue their development through to the release of pollen.
  31. Serology The branch of science dealing with the measurement and characterization of antibodies and other immunological substances in body fluids, particularly…
  32. serum The clear liquid part of the blood that remains after blood cells and clotting proteins have been removed.
  33. serum albumin The main protein in blood plasma. Low levels of serum albumin occur in people with malnutrition, inflammation, and serious liver and kidney disease.
  34. severe combined immunodeficiency (SCID) A disease affecting the immune system. SCID is fatal if affected individuals do not receive bone marrow transplants. See also antibody
  35. sewage treatment A widespread biotechnological processes in developed economies. Methods vary widely, but all are designed for the biological break-down of human and…
  36. sex chromosome Differentiated chromosome which is responsible for the determination of sex of the individual.
  37. sex determination Any method by which the distinction between males and females is established in a species, particularly at an early stage of foetal development.
  38. sex duction The incorporation of bacterial genes into F factors and their subsequent transfer, by conjugation, to a recipient cell.
  39. sex factor A bacterial episome (e.g. the F plasmid in E. coli ) that enables the cell to be a donor of genetic material.
  40. sex hormones Steroid hormones that control sexual development in animals.
  41. sex linkage Referring to genes present on one of the sex chromosomes, thus genetically linked to the sex of the individual.
  42. sex mosaic Synonym of gynandromorph.
  43. sex-influenced dominance The tendency for gene action to vary between the sexes within a species. For example, the presence of horns in some breeds of sheep appears to be dominant…
  44. sex-limited Expression of a trait in only one sex; e.g. milk production in mammals; egg production in chickens.
  45. Sex-linked Located on the X chromosome. Sex-linked (or x-linked) diseases are generally seen only in males. See also gene, mutation
  46. sexed embryos Embryos separated according to sex.
  47. Sexual reproduction The process where two cells (gametes) fuse to form one hybrid, fertilized cell. See Asexual reproduction, Gamete, Hybrid.
  48. shake culture An agitated suspension in culture providing adequate aeration for cells in the liquid medium.
  49. shaker A platform, with set or variable speed control, used to agitate vessels containing liquid cell cultures. Also described as a platform shaker.
  50. Shear Literally the sliding of one layer across another, with deformation and fracturing in the direction parallel to the movement.
  51. Shine-Dalgarno sequence A conserved sequence of prokaryotic mRNAs that is complementary to a sequence near the 5' terminus of the 16S ribosomal RNA and is involved in the…
  52. shoot apex See: shoot tip.
  53. shoot differentiation The development of growing points, leaf primordia and finally shoots from a shoot tip, axial bud, or callus surface.
  54. shoot tip The terminal bud (0.1 - 1.0 mm) of a plant, which consists of the apical meristem (0.05 - 0.
  55. shoot-tip graft A shoot tip or meristem tip grafted onto a prepared seedling or micropropagated rootstock in culture.
  56. short interspersed nuclear element (Abbreviation: SINE ). Families of short (150-300 bp), moderately repetitive DNA elements of eukaryotic genomes.
  57. short-day plant A plant which will not flower until triggered to do so by exposure to one or a number of dark periods equal to or longer than its critical period.
  58. shotgun genome sequencing A strategy for sequencing a whole genome, in which the genomic DNA is initially fragmented into pieces small enough to be sequenced.
  59. Shotgun method Sequencing method that involves randomly sequenced cloned pieces of the genome, with no foreknowledge of where the piece originally came from.
  60. shotgun sequencing An approach used to decode an organism's genome by shredding it into smaller fragments of DNA which can be sequenced individually.
  61. shuttle vector A plasmid capable of replicating in two different host organisms because it carries two different origins of replication and can therefore be used to…
  62. sib-mating The deliberate crossing of siblings. Generally done where self-incompatibility prevents the production of self-fertilized progeny.
  63. sickle cell disease (SIH-kul sel dih-ZEEZ) An inherited disease in which the red blood cells have an abnormal crescent shape, block small blood vessels, and do not last as…
  64. Side population (SP) stem cell Two examples of multipotent stem cell populations found in bone marrow and skeletal muscle. SPs are not yet fully characterized.
  65. siderophore A low molecular weight entity that binds very tightly to iron. Siderophores are synthesized by a variety of soil micro-organisms to ensure that the…
  66. sieve cell A long and slender sieve element in vascular plants, characterized by relatively unspecialized sieve areas and tapering end walls that lack sieve plates.
  67. sieve element The phloem cell concerned with longitudinal conduction of food materials.
  68. sieve plate Perforated wall area in a sieve tube element, through which strands connecting sieve tube protoplasts can pass.
  69. sieve tube A tube within the phloem tissue of a plant, composed of joined sieve elements.
  70. sigma factor The sub-unit of prokaryotic RNA polymerases responsible for the initiation of transcription at specific initiation sequences.
  71. signal peptide See: signal sequence.
  72. signal sequence A stretch of 15-30 amino acid residues at the N terminus of a protein, which is thought to enable the protein to be secreted (pass through a cell…
  73. signal transduction (SIG-nul trans-DUK-shun) The process by which a cell responds to substances in its environment.
  74. Signal transduction pathways Relay of a signal by the conversion from one physical or chemical form to another.
  75. Signal-to-Noise Ratio A specifically produced response (signal) compared to the response level (noise) when no specific stimulus (activity) is present.
  76. Signals Internal and external factors that control changes in cell structure and function.
  77. silencing Loss of gene expression either through an alteration in the of a structural gene, or its regulatory region; or because of interactions between its…
  78. silent mutation See: mutation.
  79. simple sequence repeat (Abbreviation: SSR). See: microsatellite.
  80. SINE Without.
  81. single copy A gene or DNA sequence which occurs only once per (haploid ) genome. Many structural genes are single copy.
  82. single domain antibody See: dAb.
  83. single node culture Culture of separate lateral bud s, each carrying a piece of stem tissue.
  84. single nucleotide polymorphism (... NOO-klee-oh-TIDE PAH-lee-MOR-fih-zum) The most common type of change in DNA (molecules inside cells that carry genetic information).
  85. Single nucleotide polymorphism (SNP) DNA sequence variations that occur when a single nucleotide (A, T, C, or G) in the genome sequence is altered.
  86. single nucleotide polymorphisms (SNPs) Common, but minute, variations that occur in human DNA at a frequency of one every 1,000 bases.
  87. single primer amplification reaction (Abbreviation: SPAR). A PCR-based genotyping technique in which genomic template is amplified with a single primer.
  88. Single-cell cloned A procedure pertaining to cells in vitro in which the descendants of a single cell are physically isolated from other cells growing in a dish, and then…
  89. single-cell line See: cell strain.
  90. single-cell protein (Abbreviation: SCP). Protein produced by micro-organisms, particularly yeast. Used as either a feed or a food additive.
  91. Single-gene disorder Hereditary disorder caused by a mutant allele of a single gene (e.g., Duchenne muscular dystrophy, retinoblastoma, sickle cell disease).
  92. single-strand conformational polymorphism (Abbreviation: SSCP). A technique for detection of mutations in a defined DNA sequence.
  93. single-strand DNA binding protein A protein that coats single-stranded DNA, preventing renaturation and so maintaining the DNA in an extended state.
  94. single-stranded DNA (Abbreviation: ssDNA). DNA molecules separated from their complementary strand, either by its absence or following denaturation.
  95. single-stranded nucleic acid Nucleic acid molecules consisting of only one polynucleotide chain. The genomes of many viruses are single-stranded DNA molecules, as are most…
  96. SIRE Male animal chosen for breeding.
  97. sister chromatid exchange (Abbreviation: SCE). Reciprocal interchanges of the two chromatid arms within a single chromosome.
  98. Site-directed mutagenesis The process of introducing spe- cific base-pair mutations into a gene.
  99. Site-Specific A term used to describe any process or enzyme which acts at a defined sequence within a DNA or RNA molecule.
  100. site-specific mutagenesis The induction of mutation s, by molecular biology techniques, in one or more specific nucleotide s within a defined coding sequence in order to create…