structures that make up a cell are called
DNA and histone proteins are packaged into structures called chromosomes. In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.Chromosomes are not visible in the cellâs nucleusânot even under a microscopeâwhen the cell is not dividing.ach chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. Chromosomes are not visible in the cellâs nucleusânot even under a microscopeâwhen the cell is not dividing.