not sure

the repetition of similar body segments.

Metamerism arises due to different alkyl chains on either side of the functional group in the molecule

For example , C4H10O represents methoxypropane (CH3OC3H7) and ethoxyethane (C2H5OC2H5).

In biology, metamerism is a linear series of body segments fundamentally similar in structure, though not all such structures are entirely alike in any single life form because some of them perform special functions.

Internal customers are those people and employees who might use your services and products, who reside in the same company. For example the computer department, and human resources department serve internal needs.

These are people outside the business who buy its goods and services.