The phrase "is made up of" refers to the composition of a thing or object. When writing, it is useful to vary your language and use synonyms to avoid repetitive phrasing. Some synonyms for "is made up of" include "consists of," "comprises," "contains," "includes," "is composed of," "is constituted by," "is formed of," "is put together of," and "is constructed from." Consider using these alternatives to add variety to your writing and avoid using the same phrase repeatedly. Using synonyms can also add depth and precision to your language, making your writing more interesting and engaging to read.