Final answer:
True. One can determine the directionality of chromosomes using a gene map. Cytogenetic mapping can estimate the distance between genetic markers on chromosomes, helping geneticists construct genetic maps.
Step-by-step explanation:
True. One can determine the directionality of chromosomes using a gene map. Cytogenetic mapping, which involves microscopic analysis of stained chromosomes, can estimate the distance between genetic markers on chromosomes. By analyzing the recombination frequency between genes, geneticists can determine if genes are linked or show independent assortment, allowing them to construct genetic maps.