Lederberg and Tatum’s experiment demonstrated that bacteria undergo genetic exchange.

TLS Online TPP Program

#Id: 3174

#Unit 3. Fundamental Processes

 In E. coli, two clusters of five ter sites each, including terk, -I, -E, -D, and -A on one side and terC, -B, -F, -G, and -H on the other, are located -100 kb on either side of this termination region.

TLS Online TPP Program

#Id: 3175

#Unit 3. Fundamental Processes

Each set of ter sites allows a replication fork into the termination region, but does not allow it out the other side.For example, replication fork 1 can pass through terC and terB into the region, but it cannot continue past terE, -D, and -A. This arrangement creates a "replication fork trap."

TLS Online TPP Program

#Id: 3176

#Unit 3. Fundamental Processes

 mtDNA replication and segregation to daughter mitochondria is stochastic.

TLS Online TPP Program

#Id: 3177

#Unit 3. Fundamental Processes

Mitochondrial segregation to daughter cells is also stochastic.

TLS Online TPP Program

#Id: 3178

#Unit 3. Fundamental Processes

When there are mtDNAs with allelic variations in the same cell, called heteroplasmy (either because of inheritance from different parents or because of mutation).

TLS Online TPP Program

#Id: 3179

#Unit 3. Fundamental Processes

Replication of mtDNA may be stochastic because there is no control over which particular copies are replicated, so that in any cycle some mtDNA molecules may replicate more times than others.