What are aliquots?

What is the difference between an aliquot and a derivative?
When a sample is divided into smaller portions, which are similar in characteristics like the parent, they are called aliquots. E.g., a 10 ml blood tube is aliquoted into 10x1 ml tubes. They only differ in quantity. Derivatives are processed outcomes of a parent specimen which differ in characteristics like type and pathological status. E.g., DNA, RNA, plasma, etc.
Is aliquot the lowest level of the specimen, and can’t have any derived specimen from it?
There are no restrictions. Derivatives can be aliquoted and, aliquots can be further processed.
If we have a tissue that will have RNA, DNA, and protein from it. Then the tissue has to be a derivative or parent specimen, right?
The tissue will be a parent specimen. RNA, DNA, Protein will be derivatives of the tissue.
Can aliquot have different information such as tissue specimen review information from their parents?
Yes, additional/different events like tissue specimen review events can be added at the child level.