Question 33

Covalent bonds connect sugar and phosphate in DNA.

Covalent bonds are the type of bonds that link the sugar and phosphate groups in the backbone of DNA, providing structural stability to the molecule.

A) hydrogen

Hydrogen bonds are weak attractions that occur between polar molecules, such as between the nitrogenous bases in DNA. However, they do not connect the sugar and phosphate groups; thus, this option is incorrect.

B) ionic

Ionic bonds involve the transfer of electrons and the attraction between positively and negatively charged ions. In the context of DNA, there are no ionic bonds connecting the sugar and phosphate; therefore, this option is also incorrect.

C) covalent

Covalent bonds are formed when atoms share electrons, which is precisely what occurs between the sugar and phosphate groups in DNA. This type of bond is crucial for maintaining the integrity of the DNA structure, making this option correct.

D) overt

The term "overt" does not refer to a type of chemical bond. It is unrelated to the context of molecular structure in DNA, making this option incorrect.

Conclusion

Covalent bonds are essential for linking the sugar and phosphate in the DNA backbone, ensuring structural stability. Other options, including hydrogen, ionic, and overt bonds, do not describe the connections between these components accurately and are therefore invalid in this context.