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.
Passionate about all things Australian. 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...which forms a tornado.ornadoes are most likely to occur when a cold front or dry line is moving into an area, providing weak to modest lift in an area of sufficient instability with strong low lev â¦ el wind shear, high helicity, and that has an inversion cap. 2 people found this useful.