Final answer:
The statement b is correct; phosphodiester bonds link nucleotides by connecting the phosphate group of one nucleotide with the 5' carbon of another, and the strands of DNA are antiparallel. Thus b is the correct option
Step-by-step explanation:
The correct statement regarding DNA structure is b: Phosphodiester bonds form between the phosphate group of one nucleotide and the 5' carbon of the adjacent nucleotide. The nucleic acid strands in DNA are indeed oriented antiparallel to each other, with one strand running in the 5' to 3' direction and the other in the 3' to 5' direction. DNA synthesis occurs antiparallel to the template strand, meaning it is always synthesized in the 5' to 3' direction. Therefore, statement d, which claims DNA is always synthesized in the 3' to 5' direction, is incorrect.
Moreover, the statement that Adenine pairs with Thymine and Guanine pairs with Cytosine is correct, with the former pair forming two hydrogen bonds and the latter forming three hydrogen bonds. It's also essential to note that the arrangement of the sugar-phosphate groups forms the backbone of the DNA molecule but does not determine the genetic code. The genetic code is determined by the sequence of bases along the strand.