Read the following statements regarding lipids: Statement I: The R group in a fatty acid could be a methyl, ethyl or higher number of - CH ₂ groups (1 carbon to 19 carbons). Statement II: Palmitic acid has 16 carbons excluding the carboxyl carbon. Statement III: Arachidonic acid has 20 carbon atoms including the carboxyl carbon. Statement IV: Oils have higher melting points than fats and hence remain as oil in winter

Step-by-step solution

Statement I is correct; the R group in fatty acids can range from 1 to 19 carbons. Statement II is incorrect; palmitic acid has 16 carbons including the carboxyl carbon, not excluding it. Statement III is correct; arachidonic acid has 20 carbon atoms including the carboxyl carbon. Statement IV is incorrect; oils have lower melting points (e.g., gingelly oil) compared to fats, which is why they remain liquid in winter. Thus, exactly two statements (I and III) are correct. Answer: Only two