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a gel-like substance used in bacterial cultures and electrophoresis

amino acid

any one of several building blocks of protein

artificial selection

the process of breeding two organisms with desirable characteristics to produce offspring that have the advantages of both parents


the combination of technology and the biological sciences


the material found in all cells that contains genetic information about that organism


a tool that allows scientists to separate mixtures of molecules according to size; usually for DNA or proteins


the way that an unseen gene is seen in an organism as an actual physical trait


a segment of DNA (on a chromosome) that contains the code for a specific trait

gene expression

(like expressed), the result of activated (turned on) genes

genetic engineering

a set of technologies that humans use to alter the genetic instructions of an organism by substituting DNA molecules

genetic recombination

the formation of a new combination of genes during sexual reproduction


the passing of traits from parent to offspring


any alteration in the sequence of DNA


the additional mixing of genetic material from a sperm and egg which results in a unique combination of genes


to copy (as in DNA)


one of the tiny structures in the cell that is the site of protein synthesis

selective breeding

the process of choosing a few organisms with desirable traits to serve as the parents of the next generations


to join two things together

subunit (nucleotide)

the section of a DNA molecule that contains a sugar, a phosphate and a nitrogenous base


the life process that involves combining simple substances into more complex substances


a characteristic that is passed from parent to offspring through genes


the process of reading a segment of DNA and turning it into a segment of mRNA; carried out in the nucleus


the process of reading a segment of mRNA and turning it into a string of amino acids; carried out at the ribosome


the trait that gets expressed in homozygous or heterozygous state


the trait that is masked in the heterozygous state, but show in the homozygous state


the genes for a trait (ex: Tt, TT, tt)


the physical make-up (ex: blue eyes, brown hair); how you appear


enzyme responsible for unzipping DNA in replication

DNA polymerase

enzyme responsible for adding nucleotides to a growing strand of DNA during replication


messenger RNA; carries transcribed DNA segment to ribosome


ribosomal RNA; makes up a ribosome


transfer RNA; carries amino acids to the ribosome for protein synthesis


a section of 3 bases of RNA read by the ribosome which tells the corresponding amino acid


the complement to the codon; carried by tRNA

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