Transcription is the process in which the DNA sequence of a gene is copied (transcribed) to make an RNA molecule. RNA polymerase is the main transcription enzyme. Transcription begins when RNA polymerase binds to a sequence called a promoter near the start of a gene (directly or through auxiliary proteins). RNA polymerase uses one of the DNA strands (the strand or template strand) as a template to make a new complementary RNA molecule. The transcript ends in a process called termination. The termination depends on sequences in the RNA that signal the end of transcription.
The hormone calcitonin, which is produced by the parafollicular or C cells of the thyroid, has the opposite effect on blood calcium levels as does PTH. I hope this helps! : )
Microtubules play an important role in cell division by contributing to the formation of the mitotic spindle, which plays a part in the migration of duplicated chromosomes during anaphase.
