Transcription is a process that makes mRNA using the DNA template strand. The enzyme RNA polymerase adds ribonucleotides complementary to the sequence of the DNA template strand. RNA lacks the "thymine" and instead has the "uracil". Adenine base in the DNA sequence is transcribed into the “uracil" base in the corresponding RNA. Similarly, "guanine" in the DNA template strand specifies the "cytosine" base in the transcribed RNA.
Therefore, if a DNA template strand has a sequence "TGCAAT", the corresponding mRNA would have a sequence of "ACGUUA".
A couple of homologous chromosomes, or homologs, are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization.
