AP BIOLOGY

Detailed explanation-1: -Okazaki fragments are short sequences of DNA nucleotides (approximately 150 to 200 base pairs long in eukaryotes) which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication.

Detailed explanation-2: -Because DNA polymerase can only synthesize DNA in a 5′ to 3′ direction, the other new strand is put together in short pieces called Okazaki fragments.

Detailed explanation-3: -Sometimes, the primase makes a primer before the lagging-strand polymerase holoenzyme finishes the previous Okazaki fragment. This acts as a signal that causes the lagging-strand polymerase to be released prematurely leaving a gap between fragments that must ultimately be repaired by loading another polymerase.

Detailed explanation-4: -There are no gaps between the Okazaki fragments until the RNA primer is removed. Both removal of primer and filling up of gap probably occur simultaneously by DNA polymerase.

Detailed explanation-5: -DNA polymerase I is recognized as an enzyme that fills any remaining gaps between Okazaki fragments and removes RNA primers with a duplex-specific 5′-3′ exonuclease activity, providing a nick that can be sealed by DNA ligase 31, 32.