Scientists have found ash in certain layers of sediment in an area in northern China. This is evidence that a volcano erupted in
the area in the past. In the same sedimentary layers, fossils of dinosaurs, birds, and early mammals have been found. How can scientists best determine when the volcano erupted?
RNA polymerase, a chemical in the cell, is answerable for making mRNA from the right quality. RNA polymerase is like DNA polymerase, yet it makes a RNA strand as opposed to a DNA strand. The promoter region of DNA Helix is attached by RNA polymerase.
It pulls in nucleotides that supplement those on the DNA strand containing the gene of interest. RNA polymerase duplicates one strand of DNA to make a stretching bit of singlestranded mRNA. RNA polymerase makes the mRNA strand in what is known as the 5' to 3' course.
Rigid skeletons are formed from materials including chitin (in arthropods), calcium compounds such as calcium carbonate (in stony corals and mollusks) and silicate (for diatoms and radiolarians).
