TLS Online TPP Program

#Id: 3182

#Unit 3. Fundamental Processes

The molecular apparatus is different in animal cell mitochondria and uses the protein dynamin, which is involved in formation of membranous vesicles

TLS Online TPP Program

#Id: 3183

#Unit 3. Fundamental Processes

The assignment of mitochondria to daughter cells at mitosis also appears to be random. Indeed, it was the observation of somatic variation in plants that first suggested the existence

of genes that could be lost from one of the daughter cells because they were not inherited according to Mendel's laws.

TLS Online TPP Program

#Id: 3184

#Unit 3. Fundamental Processes

In some situations a mitochondrion has both paternal and maternal alleles. This has two requirements: that both parents provide alleles to the zygote (which of course is not the

case when there is maternal inheritance.

TLS Online TPP Program

#Id: 3185

#Unit 3. Fundamental Processes

Mitochondrial DNA replicates by increasing the number of genomes in proportion to mitochondrial mass, but without ensuring that each genome replicates

the same number of times.

TLS Online TPP Program

#Id: 3186

#Unit 3. Fundamental Processes

Mitochondria use different origin sequences to initiate replication of each DNA strand

Replication of the H strand is initiated in a D loop.

Replication of the L strand is initiated when its origin is exposed by the movement of the first replication fork.

TLS Online TPP Program

#Id: 3187

#Unit 3. Fundamental Processes

Replication starts at a specific origin in the circular duplex DNA. Initially, though, only one of the two parental strands (the H strand in mammalian mitochondrial DNA) is used as a

template for synthesis of a new strand. 

Synthesis proceeds for only a short distance, displacing the original partner (L) strand, which remains single-stranded,