  We have presented the basic knowledge on the structure of molecules coding
the genetic information, mechanisms of transfer of this information from DNA to
proteins and phenomena connected with replication of DNA. In particular, we
have described the differences of mutational pressure connected with
replication of the leading and lagging DNA strands. We have shown how the
asymmetric replication of DNA affects the structure of genomes, positions of
genes, their function and amino acid composition. Results of Monte Carlo
simulations of evolution of protein coding sequences have shown a specific role
of genetic code in minimizing the effect of nucleotide substitutions on the
amino acid composition of proteins. The results of simulations were compared
with the results of analyses of genomic and proteomic data bases. This chapter
is considered as an introduction to further chapters where chromosomes with
genes represented by nucleotide sequences were replaced by bitstrings with
single bits representing genes.
