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extremely poisonous or injurious


(genetics) modification of a cell or bacterium by the uptake and incorporation of exogenous DNA


a virus that is parasitic in bacteria


a phosphoric ester of a nucleoside


a sugar that is a constituent of nucleic acids

nitrogenous base

an organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA


a colorless crystalline nitrogen-containing organic base


a heterocyclic organic compound with a penetrating odor

base-pairing rules

the rules stating that cytosine pairs with guanine and adenine pairs with thymine in DNA, and that adenine pairs with uracil in RNA

complementary base pair

the nucleotide bases in one strand of DNA or RNA that are paired with those of another strand; adenine pairs with thymine or uracil, and guanine pairs with cytosine

base sequence

the order of nitrogenous bases on a chain of DNA

dna replication

the process of making a copy of DNA


an enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands

replication fork

A Y-shaped region on a replicating DNA molecule where new strands are growing.

dna polymerase

enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

semi-conservative replication

in each new DNA double helix, one strand is from the original molecule, and one strand is new


a change or alteration in form or qualities

ribonucleic acid

(biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes


(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA


the act of uniform movement

protein synthesis

the formation of proteins by using information contained in DNA and carried by mRNA


a pentose sugar important as a component of ribonucleic acid

messenger RNA

the template for protein synthesis

ribosomal RNA

type of RNA that makes up the major part of ribosomes

transfer RNA

short-chain RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according

rna polymerase

enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription


someone who is an active supporter and advocate

termination signal

a specific sequence of nucleotides that marks the end of a gene

genetic code

the ordering of nucleotides in DNA molecules that carries the genetic information in living cells


a specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid


group of three bases on a tRNA molecule that are complementary to an mRNA codon


the ordering of genes in a haploid set of chromosomes of a particular organism

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