Question

Refer to the given reactions.
I. Guanine $+X⟶$ Guanosine
II. Guanosine $+Y⟶$ Guanylic acid

• A. (X)-Phosphate group, (Y)-Sugar molecule
• B. (X)-Sugar molecule, (Y)-Phosphate group
• C. (X)-Sugar molecule, (Y)-Nitrogenous base
• D. (X)-Nitrogenous base, (Y)-Sugar molecule

Answer 1

Answer: (B)

Option (b) is correct and can be explained as follows
I. $\underset{\text{(Nitrogen base)}}{\mathrm{Guanine}}$ +$\underset{\text{(Sugar molecule)}}{X}⟶\underset{\text{((Nucleoside)}}{\mathrm{Guanosine}}$
II. $\underset{\text{(Nucleoside)}}{\mathrm{Guanine}}$ +$\underset{\text{(Phosphate group)}}{Y}⟶\underset{\text{(Nucleotide)}}{\text{Guanylic acid}}$