In DNA the sugar used is called deoxyribose whereas in RNA the sugar is ribose (hence DNA and RNA). The important structural difference between the two types of RNA is that mRNA takes on the shape of a line whereas tRNA has a clover-like shape.
The pollutants in 1970 were the highest since recorded history and are declining steadily.
They surround and engulf foreign objects and organisms- process called phagocytosis
