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.
Rating Newest Oldest. Best Answer: A cold front is usually associated with tornado formation. Cold fronts are fronts with cool, dry air that dominate over warm, moist air. Since warm air rises, and cool air is in the way, something has to happen.ating Newest Oldest. Best Answer: A cold front is usually associated with tornado formation. Cold fronts are fronts with cool, dry air that dominate over warm, moist air. Since warm air rises, and cool air is in the way, something has to happen.