Question

According to Watson and Crick's model of DNA, sequencing the deoxyribonucleotides are joined together by a phosphodiester bond between.
A. 3’hydroxyl of deoxyribose sugar of nucleotide and a free 5’ phosphate group on sugar residues of the other nucleotide.
B. 5’hydroxyl of sugar a nucleotide of a free 3’ phosphate group on sugar residue of other nucleotides.
C. Both A and B.
D. None of the above.

Answer 1

Hint: First described by Watson and Crick, the structure of the DNA double helix in 1953 using x-ray diffraction data of DNA fibers obtained by R. Franklin and Mr. Wilkins. The scientists named Watson, Crick, and Wilkins were nominated for an award in 1962 Nobel Prize from medicine for discovering the molecular structure of DNA.

Complete answer:
A. 3’hydroxyl of deoxyribose sugar of nucleotide and a free 5’phasphate group on sugar residue of another nucleotide: Any purine or pyrimidine (cytosine and thymine in DNA). A double structure of DNA was proposed by crick and Watson in 1953 in which two antiparallels (I, e 5’-3’ and 3’-5’) polynucleotide chains from a right-handed helix (I.e, we need to look on the centreline of the helix, the strands are turned clockwise). Naturally, occurring DNA usually consists of right-handed helices with phosphate backbone over. The inside the helix and the sugar, hydrophobic base is located “backbone” on the outside. Constructed they are facing everyone and are paired according to defined rules as a result of hydrogen and formation; adenine always pairs with thymine or uracil and guanine with cytosine. Complementary bases are bound by the more common Watson-crick pairing. The double-stranded structure is further stabilized by hydration of the phosphate groups had by hydrophobic interaction between the aromatic ring systems that result in the staking of the bases.

B.5’hydroxyl of sugar or nucleotide of a free 3’phosephate group on the sugar residue of another nucleotide: All nucleotides in a polynucleotide chain have the same relative orientation. DNA and RNA forms phosphodiester bonds from 3’-5’ direction. The primary structure of DNA and RNA. The process of formation proceeds in a 5’- 3’ direction. The common representation of DNA and RNA sequence nucleotides are written from 3’-5’ direction.

Hence, the correct answer is option (A).

Note: Double helix model was proposed by Watson-crick this describes the features of the B form of DNA. Although there are many other forms of communication of DNA, (such as A-, C-, Z- form are very long from the B form. DNA sequences are the bases that undergo hydration of chemical reaction, the type, and concentration of metal ions in solution.