Learning the "talk", a glossary of biotechnology terms.

Cell and molecular biology:

• Prokaryote – the single cell organisms (including viruses, bacteria, and algae) that lack a nuclear membrane to enclose the genetic material.
  
  
• Eukaryote – higher organisms that have a nucleus and genetic material organized into chromosomes.
  
  
• Genome – all the genetic information necessary to construct an organism. All this information is arranged in packets called chromosomes in cells. Usually a number of chromosomes are required to hold all the information for an organism.
  
  
• Chromosome – a sequence of DNA wrapped up in protein. Humans have 46 chromosomes that carry all their genetic information. A linseed plant has 36.
  
  
• DNA – deoxyribonucleic acid. It is made of four small chemical bases: thymine, guanine, adenine and cytosine abbreviated as T, G, A and C. The bases are linked together in long chains supported by a chemical backbone. The base pairs are always matched A-T and G-C. The strands of bases are twisted to form a double helix. A specific set of base pairs on a DNA strand makes up a gene.
  
  
• Gene – a unit of heredity. Originally one gene was the information for one protein. You can think of a gene as a recipe used to make a protein. Genes are encoded as a sequence of base pairs on a DNA molecule. So DNA is like a cookbook with a string of recipes laid out end to end.
  
  
• Proteins – are chemicals that provide structure, physical characteristics or regulate chemical reactions in an organism. If they regulate a chemical reaction they are called enzymes.
  
  
• Homologous – if the DNA base sequence of two pieces of DNA are similar, they are said to be homologous. Each strand of DNA in the pairs that make up your genome is identical so they could be called extremely homologous.
  
  
• Mitosis – the process of doubling the genome followed by cell division so that each daughter cell gets two sets of chromosomes.
  
  
• Meiosis – the process in which the pairs of chromosomes are split up so that each sperm or egg (sex cells) gets one of each pair or half the chromosomes.
  
  
• Exchange or crossing over – chromosomes come in contact with one another in the process of meiosis and exchange genetic material. So the chromosomes that end up in the sperm or the egg can be somewhat different from those in the original pair.
  
  
• Mutation – a change in the DNA, regardless of the cause. Chemicals, UV light, can cause mutation or spontaneously by means we don’t understand. It might happen in mitosis in the process of doubling the chromosome if a mistake is make in copying the DNA.

Genetics:

• Haploid – one of each chromosome or half the chromosome compliment (found in sperm and egg after meiosis)
  
  
• Diploid – two of each chromosome or the full chromosome compliment (found in somatic or non-sex cells after mitosis)
  
  
• Heterozygous – the pair of genes (representing one trait or allele) differ i.e. Aa or Bb
  
  
• Homozygous – the pair of genes (representing one trait or allele) are identical, i.e. aa or BB or AA
  
  
• Dominant – only one gene (of the pair of chromosomes) is necessary for the trait to be expressed. Such traits are usually expressed in capital letters, i.e. A or W or B
  
  
• Recessive – both genes (of the pair of chromosomes) are necessary for the trait to be expressed. Such traits are usually expressed in small letters, i.e. a, b or w.
  
  
• Phenotype – the outward appearance of an organism, i.e. brown eyes although one can carry the recessive gene for blue eyes that is not seen.
  
  
• Genotype –the genetic makeup of an organism i.e. the actual gene composition whether or not all variance is expressed in the phenotype.

Plant Science:

• Pistil – the functional female organ in plants containing a stigma leading to a swollen base (ovary) which contains the female sex cells or female gametes. The male pollen must reach the ovary in order to fertilize the plant and produce ‘seeds.’
  
  
• Stamen – the functional male organ in plants containing anthers where the male sex cells or gametes are produced. In plants the ‘sperm’ is the pollen.
  
  
• Selection – observing the characteristics of plants and choosing (selecting) to use the seeds of only those plants that have desired or superior characteristics. An early example was the use of certain potato eyes at different elevations in the Andes.
  
  
• Crossing – the male pollen from one identified superior plant is collected and transferred to the female part (stigma) of another superior plant.
  
  
• In-breeding – the process of promoting self fertilization (self to self), crossing among siblings (sib-sib cross) or crossing the offspring back to one parent. This produces distinct lines of plants with homozygous traits. Some with undesirable traits (perhaps recessive) will die off; others will survive with uniform and sometimes desirable traits. This is called the fixing of genetic characteristics.
  
  
• Hybrid plants - are created by artificial pollination carried out by the plant breeder using two highly inbred strains. Inbred strains tend to be homozygous (AA or aa) and the result of the cross usually produce larger seed crops than either parent – called hybrid vigor. However the seeds produced by this hybrid vigor cannot be used in the next season because the plants that result tend to have undesirable characteristics (and the seeds may not have the germination rate desired).
  
  
• Principles of taxonomy for naming organisms –
  • Kingdom – example animals (including all animals)
  • Phylum – example chordata (including all vertebrates, sea squirts, amphioxus, etc.
  • Class – example mammalia (including all animals that give milk)
  • Order – example carnivora (including bears, dogs, cats, seals, etc.)
  • Family – example felidae (including cats, leopard, lion, etc.)
  • Genus – example panthera (including leopard, lion and tiger)
  • Species – example tigris (the tiger)
    
    
• Cultivar or variety -- plants within the same species that have somewhat different properties or external traits. These are usually produced and maintained by selective breeding.
  

Genetic Engineering:

• Plasmids – a small circular piece of DNA found in some bacteria. It is present in addition to the bacterial genome. Scientists have found the plasmid useful for genetic engineering.
  
  
• Genetic engineering – inserting a gene or genes from one organism into another using molecular laboratory techniques.
  
  
• Recombinant DNA or rDNA. Artificially splicing pieces of DNA together, usually using specialized enzymes, a necessary step for genetic engineering.
  
  
• Genetically modified – widely used to indicate the insertion of DNA from one organism to another, usually by molecular techniques.
  
  
• Genetically modified organism (GMO) – the organism resulting from a genetic modification.
  
  
• Transformation – the act of inserting genetic material into a cell or organism.
  
  
• Transgenic – adjective or descriptor for an organism carrying foreign or artificially inserted genetic material. So a plant carrying the Bt gene would be a transgenic plant.

Additional Sources:

FAO Glossary of Biotechnology and Genetic Engineering - “The Food and Agriculture Organization of the United Nations, provides a very extensive glossary of terms associated with the very broad field of biotechnology. It contains terms currently in use in biotechnology, genetic engineering and closely allied fields as well as terms from applied biotechnology that are important to FAO’s work in the areas of plant and animal genetic resources, food quality and plant protection.” J. Lynne Brown, Associate Professor, Food Science