Ch. 16 The Molecular Basis of Inheritance Flashcards
a molecule of DNA is copied
a change in genotype and phenotype due to the assimilation of external DNA by a cell
two strands and spacing of nitrogenous bases along them
two sugar-phosphate backbones, their subunits run in opposite directions
Watson and Crick's model predicts that when a double helix replicates, each of the two daughter molecules will have one old strand, from the parental molecule, and one newly made strand.
origins of replication
short stretches of DNA having a specific sequence of nucleotides
a Y-shaped region where the parental strands of DNA are being unwound
enzymes that untwist the double helix at the replication forks, separating the two parental strands and making them available as template strands
single-strand binding proteins
bind to the unpaired DNA strands, keeping them from re-pairing. The untwisting of the double helix causes tighter twisting and strain ahead of the replication fork.
helps relieve this strain by breaking, swiveling, and rejoining DNA strands.