Final answer:
The term that corresponds to the loss of a portion of a chromosome is a deletion, which involves a missing segment of DNA and can result in multiple genes being absent.
Step-by-step explanation:
The term that is best described by the statement “A portion of a chromosome is lost” is deletion. A deletion refers to a genetic anomaly where a segment of DNA is missing from a chromosome, which can result in the loss of several genes. This is not the same as a translocation, where a segment breaks off and attaches to a different chromosome, nor is it a karyotyping technique used to visualize chromosomes, or cloning, which involves creating a genetically identical copy of an organism or cell.