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