The helicase DnaB is responsible for interacting with the primase DnaG to initiate each Okazaki fragment.

TLS Online TPP Program

#Id: 3044

#Unit 3. Fundamental Processes

In mammalian systems (where the DNA polymerase does not have a 5'- 3' exonuclease

activity), Okazaki fragments are connected by a two-step process. Synthesis of an Okazaki fragment displaces the RNA primer of the preceding fragment in the form of a "flap’’.

The base of the flap is cleaved by the enzyme FEN1 (flap endonuclease 1 ) .

TLS Online TPP Program

#Id: 2324

#Unit 3. Fundamental Processes

Group II mitochondrial introns are excised by the same mechanism as nuclear pre-mRNAs via a lariat that is held together by a 2’–5’ bond.

TLS Online TPP Program

#Id: 9799

#Unit 6. System Physiology – Plant

When Pr molecules are exposed to red light, most of them absorb it and are converted to Pfr, but some of the Pfr also absorbs the red light and is converted back to Pr because both Pr and Pfr absorb red light. 

TLS Online TPP Program

#Id: 3977

#Unit 2. Cellular Organization

The degree of supercoiling of bacterial DNA is maintained by regulation of the net activity of topoisomerases, I and II.

TLS Online TPP Program

#Id: 6333

#Unit 8. Inheritance Biology

Environmental Sex Determination