ABSTRACT
This chapter presents a critical assessment of several terminologies being used for additional DNA sequences has been the subject matter. The discovery of repeated DNA sequences in plants assisted considerably the interpretation of chromosome structure in terms of function and evolution. Nucleotypic DNA is also repeated, dispersed, and may have the property of movement. Dynamic DNA has a distinctive role in messenger processing, reshuffling of exons, and maintenance of integrity of chromosome structure by providing padding at respective loci. Selfish DNA sequences, having the properties of mobility and capacity of transfer between different chromosomes, have been designated as parasitic or symbiotic DNA. The initiation of replication involves certain parts of comparatively long palindromes which are identical or very similar in the nucleotide sequences. The spacer sequences have also been noted to be heterogenous and located in 5-histone gene clusters in mammals and other organisms. A new class of human interspersed repeated sequences different from the Abr family has been recorded.
