Postulate of Darwin

Geometric increase 

Limited food & Space

Struggle for existence 

Variation 

 Natural selection

Inheritance of useful characters

Speciation

TLS Online TPP Program

#Id: 7894

#Unit 2. Cellular Organization

The mtDNAs of most multicellular animals are approximately 16-kb circular molecules that encode intron-less genes compactly arranged on both DNA strands.

TLS Online TPP Program

#Id: 7895

#Unit 2. Cellular Organization

Vertebrate mtDNAs encode 2 rRNAs, 22 tRNAs, and 13 proteins involved in electron transport and ATP synthesis. 

TLS Online TPP Program

#Id: 7896

#Unit 2. Cellular Organization

The smallest mitochondrial genomes in Plasmodium, are only about 6 kb, encoding three proteins and the mitochondrial rRNAs.

Arabidopsis thaliana, has 366 kb of mtDNA and cucurbit plants have about 2 Mb of mtDNA.

TLS Online TPP Program

#Id: 7897

#Unit 2. Cellular Organization

Chloramphenicol, blocks protein synthesis by bacterial and mitochondrial ribosomes

Cycloheximide, does not affect protein synthesis by mitochondrial ribosomes

TLS Online TPP Program

#Id: 7898

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 7899

#Unit 2. Cellular Organization

Only 22 tRNAs are required for mitochondrial protein synthesis. The normal codon–anticodon pairing rules are relaxed in mitochondria, so that many tRNA molecules recognize any one of the four nucleotides in the third (wobble) position, allowing four codons to be recognized by a single tRNA.