Twin and Siamois encode homeodomain transcription factors and are expressed in the organizer

TLS Online TPP Program

#Id: 3190

#Unit 3. Fundamental Processes

To replicate mammalian mitochondrial DNA, the short strand in the D loop is extended. The displaced region of the original L strand becomes longer, expanding the D loop

TLS Online TPP Program

#Id: 3191

#Unit 3. Fundamental Processes

In mtDNA, The existence of D loops exposes a general principle: An origin can be a sequence of DNA that serves to initiate DNA synthesis using om strand as a Template.

TLS Online TPP Program

#Id: 3192

#Unit 3. Fundamental Processes

In the case of mitochondrial DNA replication, the origins for replicating the complementary strands lie at different locations

TLS Online TPP Program

#Id: 3193

#Unit 3. Fundamental Processes

Origins that sponsor replication of only one strand are also found in the rolling circle mode of replication.

TLS Online TPP Program

#Id: 3198

#Unit 3. Fundamental Processes

Errors in replication and damage to DNA have two consequences;
One is, of course, the introduction of permanent changes to the DNA (mutations), which can alter the coding sequence of a gene or its regulatory sequences.
The second consequence is that some chemical alterations to the DNA prevent its use as a template for replication and transcription

TLS Online TPP Program

#Id: 3199

#Unit 3. Fundamental Processes

Mismatches between the strands of DNA are one of the major targets for excision repair systems. Mismatch repair (MMR) is accomplished by scrutinizing DNA for apposed bases that do not pair properly