A researcher wanted to test the effect of different chemical agents on double-stranded DNA (dsDNA). dsDNA was taken in tubes (A, B, C, and D), and four different agents were added individually to each tube. The researcher, however, forgot to label them. The properties of the added chemical agents on dsDNA were analyzed. The possible product (Column X) and the specific action of the chemical agents are listed in Column Y.

Column X		Column Y
A.	Nucleotides	I.	Breaks hydrogen bond
B.	Only nitrogenous bases	II.	Removes phosphate group
C.	Nucleosides	III.	Breaks phosphodiester bond
D.	ssDNA	IV.	Breaks N-glycosidic bond

Which one of the following options represents all correct matches between Column X and Column Y?

Correct option is B

Correct Answer:  A-iii, B - iv, C- ii, D - i

• A (Nucleotides) and iii (Breaks phosphodiester bond): Nucleotides in a DNA chain are held together by phosphodiester bonds between the sugar and phosphate groups. Breaking these bonds would disrupt the nucleotide structure.
• B (Only nitrogenous bases) and iv (Breaks N-glycosidic bond): The nitrogenous bases are linked to the sugar in a nucleotide by N-glycosidic bonds. Breaking these bonds would separate the base from the sugar.
• C (Nucleosides) and ii (Removes phosphate group): Nucleosides are components of nucleotides minus the phosphate group. The chemical agent that removes the phosphate group would act on nucleosides.
• D (ssDNA) and i (Breaks hydrogen bond): ssDNA consists of a single strand, and breaking hydrogen bonds is the correct action when dealing with complementary strands of DNA, typically seen during processes like denaturation.

Information Booster:

1. Nucleotides are the building blocks of DNA and RNA and consist of a nitrogenous base, a sugar, and a phosphate group.
2. Phosphodiester bonds are crucial for linking nucleotides together to form DNA or RNA strands.
3. N-glycosidic bonds link the nitrogenous bases to the sugar molecule in both nucleotides and nucleosides.
4. Nucleosides are similar to nucleotides, except they lack the phosphate group.
5. Hydrogen bonds between complementary base pairs are essential for stabilizing the double-stranded structure of DNA.
6. ssDNA is a single-stranded form of DNA that may need to be denatured or altered for certain processes in molecular biology.