Why is it difficult to observe individual chromosomes with a light microscope during interphase? view available hint(s) why is it difficult to observe individual chromosomes with a light microscope during interphase? they have uncoiled to form long, thin strands. they leave the nucleus and are dispersed to other parts of the cell. sister chromatids do not pair up until division starts. the spindle must move them to the metaphase plate before they become visible. the dna has not been replicated yet?