A trait can evolve by sexual selection if it increases a male’s overall fitness, even if it decreases survival.

Exaggerated secondary sexual traits are favored by sexual selection because they increase male mating success.

TLS Online TPP Program

#Id: 742

#Unit 3. Fundamental Processes

The phosphodiester bond is formed in an SN2 reaction in which the hydroxyl group at the 3’ end of the primer strand attacks the a-phosphoryl group of the incoming nucleoside triphosphate.

TLS Online TPP Program

#Id: 743

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 744

#Unit 3. Fundamental Processes

free energy for this reaction is rather small (DG–3.5 kcal/mol).

TLS Online TPP Program

#Id: 745

#Unit 3. Fundamental Processes

Additional free energy for the formation of phosphodiester bond is provided by the rapid hydrolysis of the pyrophosphate into two phosphate groups by an enzyme known as pyrophosphatase:

 

TLS Online TPP Program

#Id: 746

#Unit 3. Fundamental Processes

Hydrolysis of pyrophosphate makes phosphodiester bond a highly favorable reaction with a DG of –7 kcal/mol, which corresponds to an equilibrium constant (Keq) of 105.

TLS Online TPP Program

#Id: 747

#Unit 3. Fundamental Processes

A:T and G:C base pairs have same geometry that’s why DNA polymerase has only one catalytic site for polymerization