If you do not have an SSN and are not eligible to obtain an SSN, but you have a requirement to furnish a federal tax identification number or file a federal income tax return, you must apply for an ITIN. By law, an alien individual cannot have both an ITIN and an SSN.
DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix.
what are the four nitrogen bases in dna and how do they base pair together phosphodiester bonds what type of bond holds the nucleotides together in the strands of a dna molecule hydrogen bonds what hold the two strands of nucleotides together between the paired nitrogen bases in a dna molecule making all the proteins an organsim needs what does dna contain the instructions or code for