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Molecular Genetics
Term | Definition |
---|---|
DNA replication | process in which chromosomal DNA is copied before mitosis or meiosis. |
Double helix | shape of a DNA molecule formed when two twisted DNA strands are coiled into a springlike structure and held together by hydrogen bonds between the bases. |
Nitrogenous base | carbon ring structure found in DNA or RNA that contains one or more atoms of nitrogen: includes adenine,guanine,cytosine,,thymine,and uracil. |
Codon | set of three nitrogenous bases that represents an amino acid: order of nitrogenous bases in mRNA determines the type and order of amino acids in a protein |
mRNA | RNA that transports information from DNA in in the nucleus to the cell's cytoplasm |
rRNA | RNA that makes up the ribosomes: clamps onto mRNA and uses its information to assemble amino acids in the correct order. |
Transcript | process in the cell nucleus where enzymes make a RNA copy of a DNA strand. |
tRNA | RNA that transports amino acids to the ribosomes |
Translation | process of converting information in mRNA into a sequence of amino acids in a protein. |
Chromosomal mutation | mutation that occurs at the chromosome level resulting in changes in the gene distribution to gametes during meiosis; caused when parts of chromosomes break off or rejoin incorrectly. |
Frameshift mutation | mutation that occurs when a single base is added or deleted from DNA; causes a shift in the reading of codons by one base. |
Mutagen | any agent that can cause a change in DNA; includes high energy radiation, chemicals,or high temperatures. |
Mutation | any change or random error in a DNA sequence. |
Point Mutation | mutation in a DNA sequence; occurs from a change in a single base pair. |
Clone | genetically identical copies of an organism or gene. |
Gene splicing | in recombinant DNA technology, the rejoining of DNA fragments by vectors and other enzymes. |
Genetic engineering | method of cutting DNA from one organism and inserting the DNA fragment into a host organism of the same or a different species. |
Plasmid | small ring of DNA found in bacterial cell that is used as a biological vector. |
Recombinant DNA | DNA made by recombining fragments of DNA from different sources. |
Restriction enzymes | DNA-cutting enzymes that can cut both strands of a DNA molecule at a specific nucleotide sequence. |
Transgenic organism | organisms that contains functional recombinant DNA from a different organism. |
Vector | means by which DNA form another species can be carried into the host cell; may be biological or mechanical. |
Gene therapy | insertion of normal genes into human cells to correct genetic disorders. |
Human genome | map of the approximately 80 000 genes of 46 human chromosomes that when mapped and sequenced,may provide information on the treatment or cure of genetic disorders. |
Linkage map | genetic map that shows the location of genes on a chromosome. |