Chromosomes are studied in histology through techniques like fluorescence in situ hybridization (FISH) and karyotyping. FISH uses fluorescent probes that bind to specific parts of chromosomes, allowing for visualization under a fluorescence microscope. Karyotyping involves staining chromosomes to produce a distinctive pattern of bands, which can be analyzed to detect structural abnormalities. These methods require high-quality tissue sections, highlighting the importance of histological preparation.