heredity+glossary

This section is for you all to keep an up to date glossary of the relvant terminology we cover in this area of study. It is important that you use your own words to explain the meaning of any terms.


 * Gene**-Basic unit of hereditary made up of a unique sequence of DNA
 * Genome-**The total genetic material within a cell, indiviudal or a species
 * Nucleotides-**the building blocks of nucleic acids (eg. DNA). Are composed of: 5 carbon sugar, nitrogenous base, phosphate group
 * Base-**Any of the four chemicals adenosine (A), thymine (T), guanine (G) and cytosine (C) present in the nucleotides of DNA (In RNA uracil (U) replaces thymine), forming linking points between strands
 * Exons-**Part of a gene which contain the base sequences which code for the amino acids needed to build a protein molecule
 * Introns-**Non-coding segments of DNA spliced between exons
 * Chromosomes-**Thread-like structures dound in the nucleus of all eukaryotic cells
 * Mutation-**Any change in the arrangement or amount of DNA in a cell or virus
 * Mutagen-**Any influence which increases the rate of a mutatition
 * RNA polymerase-**An enzyme necessary for transcription
 * Transcription-**The production of a molecule of pre-mRNAfrom a DNA template
 * Restriction enzymes/endunucleases**-A Bacterial enzyme that is specialised to recognise a particular DNA sequence and cut the DNA at the recognition site. AKA molecular scissors
 * Recognition site**- A sequence of bases in a DNA molecule which is cut by a particular restriction enzyme
 * Gene probes**-A single stranded piece of DNA (or RNA) sequences that is complimentary to a part of the target DNA sequece and is used to identify the location of a particular gene or DNA fragment
 * DNA Ligase-**An enzyme that is used to join pieces of DNA together
 * Reverse Trascriptase-**An enzyme that is used in genetic engineering to produce copy/complimentary DNA (cDNA) from a messenger RNA (mRNA) template. It's transcription in reverse
 * Genetic Modifications-**The transfer of specific genes from one organism into the genome of another organism, usually of a different species
 * Transogenic organisms-**Organisms that have been genetically modifed
 * Gel Electrophoresis-**A technique used for seperating fragments of DNA according to their size. Fragments migrate through a gel at different rates when driven by a drop in electric volt.
 * Restriction fragment length polymorphisms**- variations in the DNA sequence of a genome that can be detected by breaking the DNA into pieces with restriction enzymes
 * DNA Profile-**Unique banding pattern on a gel when an individuals DNA is cut with restriction enzynes
 * DNA profiling/DNA fingerprinting-**Uses a pattern of reperated DNA sequences (called short tandem repeats-STRs) that are unique to an individual to identify a particular persons DNA.
 * Southern Blot-**A technique used to look for particular bands on a gel, that is to identify an individual fragment (sequence) of DNA
 * Hybridisation-**Means that 2 strands of DNA are allowed to combine, by base-pairing rules. The degree of hybridisation depends on the degree of similarity or complimentarity between the strands
 * Polymerase Chain Reaction-**A technique used to make millions of pure copies (to amplify) of a piece of DNA in a test tube
 * Primer-**A short, single stranded sequence of DNA (or RNA) that is complemntary to part of the target DNA. It binds to a section of DNA that has been targeted for amplication in PCR
 * DNA Sequencing-**The determination of the acutal sequences of nucleotides in a DNA strand.
 * Recombinant DNA-**DNA formed from fragments of DNA from different organisms
 * Karyotyping-**A process of sorting chromosomes according to size.
 * cDNA-**Complementary DNA made from a template strand of mRNA by the action of the enzyme reverse transcriptase