<prompt> The DNA segment from which the primary mRNA transcript is copied or transcribed is called:-Coding strandInitiator methionine domainTemplate strandTranslation unit  <response>: DNA segment from which the primary mRNA transcript is copied or transcribed is called as Template strand Template strand : Strand which is being acted upon by RNA polymerase. mRNA produced resembles the sequence of the opposite strand except U in place of T. The opposite strand is known as coding, sense or plus strand. 