Three modes of DNA replication appear possible: –Conservative Original helix is conserved and two newly synthesized strands come together –Semiconservative Each replicated DNA molecule consists of one "old" strand and one new strand –Dispersive Parental strands are dispersed into two new double helices
Three Attributes of DNA Replication Shared by All Organisms 1.Each strand of the parental DNA molecule remains intact during replication 2.Each parental strand serves as a template for formation of an antiparallel, complementary daughter strand 3.Completion of replication results in the formation of two identical daughter duplexes composed of one parental and one daughter strand 12
DNA replication starts when a large protein complex (pre-replication complex) binds to a region called origin of replication (ori). In E. coli, DNA is unwound and replication proceeds in both directions, forming two replication forks.
Checkpoint In the figure shown, the leading strand grows continuously _______ at its _______ end. a.backward; 5′ b.forward; 5′ c.backward; 3′ d.forward; 3′
Checkpoint In the figure shown, what best describes Strand B? a.It is the lagging strand. b.It is the leading strand. c.It is the Okazaki strand. d.There is not enough information given. Strand A Strand B 5’5’ 3’3’