Distinct threadlike structures containing genetic information are called?

They may be called several things. They could be called Chromosomes (however these are when the genetic information has been aggregated into bodies (usually resembling an X). It can be called DNA (meaning deoxyribonucleic acid) which is the long strand of information made of up base pairs which resembles a twisted ladder. A small segment of that ladder which produces only one protein may be called a Gene. (from whence we get the term genetics).

When DNA is being used to make pieces of the cell and produce stuff in genera, it is transcoded into RNA (Ribonucleic Acid) which is a temporary form of the genetic information which can be taken from the nucleus of the cell where the DNA is stored and turned into protein elsewhere. This form of RNA is known as Messenger (m)RNA.

containing genetic information: Chromatin condenses to form chromosomes. These distinct, threadlike structures contain the genetic information or DNA.