Eukaryotic organisms, genetics

Despite the differences in nuclear structures between prokaryotes and eukaryotes, the genetic code, i.e. the combination of bases which does for a particular amino acid in the process of protein synthesis, is the same as it is in all living organisms. 

The cell cycles of eukaryotic organisms are complex and not only involve changes in morphology but also variation in the genetic complement of the cell. Typically the... 

Much of the chemistry of the cell is common to all living systems and is directed towards ensuring growth and cell multiplication, or at least the survival of the cell. Organisms also share various structural characteristics. They all contain genetic material (DNA), membranes (the boundary material between the cell and the environment), cytoplasm (small particulate materials, ribosomes and enzyme complexes), and cell walls or surfaces (complex structures external to the membrane). In addition, there are various distinct membrane-bound organelles in eukaryotic organisms which have specialised functions within the cell (Tables S.4, 5.5 and 5.6)(8-, 7). 

The tertiary structure of DNA is complex. DNA does not normally exist as a straight linear polymer, but as a supercoiled structure. Supercoiiing is associated with special proteins in eukaryotic organisms. Prokaryotic organisms have one continuous molecule white eukaryotes have many (e.g. humans have 46). Viruses also contain nucleic acids and their genetic material can be either DNA or RNA. 

In eukaryotic organisms, transcription regulation is a complex process that demands coordinated interaction of several genetic elements. The efficiency of this process mainly depends on the promoter/enhancer sequences, the copy number of the gene, and the structure and elements present at the insertion site in the host s chromatin. On the other hand, the co-transcriptional modifications (capping, splicing, polyadenylation, and transport to cytoplasm) on the primary transcript determine the stability, turnover rate, and translational capacity of the future mRNA. 

DNA is the genetic material in all prokaryotic and eukaryotic organisms. It may be either DNA or RNA in viruses. The genetic material must fulfill certain basic requirements ... 

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