The complex of DNA and protein that makes up a eukaryotic chromosome is properly called __________.

• A. a chromatid
• B. a centromere
• C. a chromoplast
• D. a centrosome
• E. chromatin

Answer: (E)

Verified step by step guidance

1. Understand that eukaryotic chromosomes are composed of DNA and proteins. These proteins help in packaging the DNA into a compact, dense shape.
2. Recognize that the term 'chromatin' refers to the complex of DNA and proteins found in the nucleus of eukaryotic cells. This structure allows the long DNA molecules to be packed into a more manageable form.
3. Differentiate between the given options: a chromatid is one half of a duplicated chromosome, a centromere is the region where two chromatids are joined, a chromoplast is a type of plastid involved in pigment synthesis, and a centrosome is an organelle that serves as the main microtubule organizing center.
4. Identify that 'chromatin' is the correct term for the DNA-protein complex that makes up eukaryotic chromosomes, as it is involved in packaging DNA and regulating gene expression.
5. Conclude that the correct answer to the problem is 'chromatin', as it accurately describes the structure and function of the DNA-protein complex in eukaryotic cells.