Q. What are those structures that appear as 'beads-on-string' in the chromosomes when viewed under electron microscope?
A) Base pairs
B) Genes
C) Nucleotides
D) Nucleosomes
Explanation
[Solution from source] DNA wrapped around histone octamers forms nucleosomes, which repeat along the chromatin fibre and look like beads on a string under the electron microscope. Base pairs, nucleotides and genes are far too small or not visible as separate beads. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.