NEET2026BiologyChapterActual
Which of the following statements are correct regarding the packaging of DNA helix in eukaryotes? A. A typical nucleosome contains 200 bp of DNA helix. B. The 'beads-on-string' structure in chromatin is clearly seen when viewed under a light microscope. C. Chromatin fibres are further coiled and condensed at metaphase stage of cell division to form chromosomes. D. Euchromatin is densely packed and stains dark. E. Euc
Options
- AA, C and E only
- BA, B and D only
- CB, D and E only
- DC, D and E only
Correct answer
A. A, C and E only
Step-by-step solution
Statement A is correct. A typical nucleosome contains about 200 bp of DNA helix wrapped around the histone octamer. Statement B is incorrect. The 'beads-on-string' structure in chromatin is observed under an electron microscope, not a light microscope. Statement C is correct. Chromatin fibres are further coiled and condensed at the metaphase stage of cell division to form chromosomes. Statement D is incorrect. Euchromatin is loosely packed and stains light, whereas heterochromatin is densely packed and stains dark.