Question

According to Philip Bell’s viral eukaryogenesis hypothesis, the presence of linear chromosomes, with centromeres and telomeres, and 5’-capping and 3’-polyadenylation of mRNA, was first provided by:

A. an endosymbiotic archaeobacterium B. an endosymbiotic gram-negative eubacterium C. a double-stranded DNA virus D. a gram-negative eubacterial host cell E. an archaeobacterial host cell

Answer 1

ANS: According to Philip Bell's viral eukaryogenesis hypothesis, the presence of linear chromosomes, with centromeres and telomeres, and 5'- capping and 3'- polyadenylation of mRNA, was first provided by:

A. an endosymbiotic archaeobacterium.

Viral eukaryogenesis hypothesis is the hypothesis of eukaryotics that is evolved from a large DNA virus in the form of an endosymbiosis with the archaeobacterium.

Later, virus evolved from the host genome.

The eukaryotic nucleus consists linear DNA, linear chromosomes with centromere, telomere, and mRNA caping. it separates transcription from the translation.

These viral genes evolved to interact with the archaeal information processing apparatus since the viru was dependent on host archaeal machinery for translation and replication.

The endosymbiotic hypothesis of the eukaryotic cell origin has been applied to the mitochondria and choloplasts origins.

Symbiogenesis at the basis of eukaryotic origins: a product of the merger by which eukaryotic cells appear and gives the information about the large scale migration of organellar DNA to the nucleus.

Cells that contains mitochondria had the bioenergetic it means to attain eukaryotic cell complexicity, so that no true intermeiates in the prokaryotic to eukaryote transition.

current verison of endosymbiotic theory evolved the host was an archaeon or an archaebacterium, not a eukaryote.

so, philip bell's hypothesis give support as large complex DNA viruses which are capable of protein biosynthesis.

so, the endosymbiotic archaeobactreium was first provided by the philip bell's viral eukaryotic hypothesis.

later on, in evolutionary period, archaeobacterial host cells also provided.