This is called a template strand because it is used as a "template"
Approximately 1,000 to 30,000 years old
<span>It was the culmination of research in the 1930s and early 1940s at the Rockefeller Institute for Medical Research to purify and characterize the "transforming principle" responsible for the transformation phenomenon first described in Griffith's experiment of 1928: killed Streptococcus pneumoniae of the virulent strain type III-S, when injected along with living but non-virulent type II-R pneumococci, resulted in a deadly infection of type III-S pneumococci.</span>
The second one would be my answer but also an answer that is not up there is that during an experiment when repeating the trials you might have to set up a new hypothesis every time and have to review the data several different times because of different results from each trial
hope this helps if not just let me know