Final answer:
In karyotyping, chromosomes are arrested in metaphase using colchicine to observe chromosomal abnormalities. Metaphase is the stage of cell division where chromosomes become condensed and visually discrete.
Step-by-step explanation:
In karyotyping, chromosomes are arrested in metaphase. Metaphase is the stage of cell division where chromosomes become condensed and visually discrete.
To observe an individual's karyotype, cells are first collected from a blood sample or other tissue and stimulated to begin actively dividing. A chemical called colchicine is then applied to arrest the chromosomes in metaphase, allowing for the analysis of chromosomal abnormalities.