Phototropism Is Mediated by the Lateral Redistribution of Auxin

In response to a directional light stimulus, the auxin produced at the tip, instead of being transported basipetally, is transported laterally toward the shaded side. Two flavoproteins, phototropins 1 and 2, are the photoreceptors for the blue-light signaling pathway that induces phototropic bending in Arabidopsis

TLS Online TPP Program

#Id: 2982

#Unit 3. Fundamental Processes

Only one DNA polymerase is the replication enzyme. The others participate in repair of damaged DNA, restarting stalled replication forks, or bypass 1ng damage in DNA.

TLS Online TPP Program

#Id: 2983

#Unit 3. Fundamental Processes

All prokaryotic and eukaryotic DNA polymerases share the same fundamental type of synthetic activity, antiparallel synthesis from 5' to 3' from a template that is 3' to 5'.

TLS Online TPP Program

#Id: 2985

#Unit 3. Fundamental Processes

A comprehensive series of such temperature-sensitive mutants in Escherichia coli identifies a set of loci called the dna genes. The dna mutants distinguish two stages of replication by their behavior when the temperature is raised

The members of the major class of quick-stop mutants cease replication immediately upon a temperature increase.

The members of the smaller class of slow-stop mutants complete the current round of replication, but cannot start another.

TLS Online TPP Program

#Id: 2986

#Unit 3. Fundamental Processes

In E. coli., DNA polymerase III, a multisubunit protein, is the replication polymerase responsible for de novo synthesis of new strands of DNA. 

TLS Online TPP Program

#Id: 2988

#Unit 3. Fundamental Processes

In E. coli DNA polymerase II is required to restart a replication fork when its progress is blocked by damage in DNA.

TLS Online TPP Program

#Id: 2989

#Unit 3. Fundamental Processes

In E. coli., DNA polymerases IV and V are involved in allowing replication to bypass certain types of damage and are called error-prone polymerases