Q.What is the relation between nucleotide and nucleoside? Give one evidence that supports the recapitulation theory. (1+1) OR What is 'Hot dilute soup'?

Nucleotide = nucleoside + phosphate; recapitulation theory is supported by embryonic features (like gill slits in the human embryo) that mirror ancestral evolutionary stages.

Nucleotide–nucleoside relation: A nucleoside is formed by the linkage of a nitrogenous base (purine or pyrimidine) to a pentose sugar (ribose or deoxyribose) via a glycosidic bond — it has no phosphate group. A nucleotide is formed when a phosphate group is further attached (by an ester bond) to the sugar of a nucleoside. So: Nucleotide = Nucleoside + Phosphate group. Nucleotides are the monomers that polymerise (via phosphodiester bonds) to form nucleic acids (DNA/RNA).

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