Final answer:
The position of the double bond closest to the methyl (CH3) end of a fatty acid is described by an omega number.
Step-by-step explanation:
The position of the double bond closest to the methyl (CH3) end of a fatty acid is described by a(n) omega number. Fatty acids are classified by the position of the first double bond relative to the methyl or 'omega' end of the carbon chain. The omega number indicates the position of the double bond between the nth carbon atom and the carbon atom next to it towards the omega (last) carbon atom.