Class A (type D) CpG ODNs (CpG-A ODNs) contain a central palindromic phosphodiester (PO) CpG sequence and a PS-modified 3â poly-G tail. The poly G tails form intermolecular tetrads that result in high molecular weight ordered structures.
Why does a tornado form when cold and hot air meet? The collision of warm and cold air is not the direct cause of a tornado, nor is it absolutely necessary. When a cold air mass pushes into a warm air mass (this is called a câ¦old front) the warmer, less dense air is forced upwards.
All tornadoes usually occur in tornado ally or in flat lands   Improved Answer: Well, in summer or spring, a lot parts of the country are windy with hot air, and cold air.. Further information:   Tornadoes need a combination of factors to form, and these factors are often associated with thunderstorms, which are most likely to occur in the warmer months.