Chapter 16The Molecular Basis of Inheritance

a change in genotype and phenotype due to the assimilation of external DNA by a cell
Bacteriophages or phages
Viruses that infect bacteria widely used as research tools in molecular genetics
Double helix
the presence of two strands
Semiconservative model
Watson and Crick'd model predicts that when a double helix replcates, each of the two daughter molecules will have one old strand, derived from the parent molecule and one newly made strand
Orgins of replication
where the replication of DNA begins
Replication fork
A Y- shaped region where the new strands of DNA are elongating
DNA polymerases
Elongation of new DNA at a replication frok is catalyzed by enzymes
DNA ligase
joins the sugar phosphate backbone s of the Okazaki fragments to create a singe DNA strand
the start of a new chain, is not DNA but a short streach of RNA
an enzyme joins RNA nucleotides to make the primer
an enzyme that untwists the double helix at the replication fork, separating the two old strands
DNA cutting enzyme
DNA at the tips of chromosomes
An enzyme that catalyzes the lengthening of telomeres. The enzyme includes a molecule of RNA that serves as a template for new telomere segments.