Questions 1-5 are based on the following text                          About fifty years ago , plant physiologists set out to grow roots , by themselves in solutions inlaborartory flasks . The scienists found that the nutrtion of isolaed roots was quite simple . They requried sugar and usual minerals and vitamins . However they , did not require organic nitrogen compounds . Thes roots got along fine on mineralinorgani nitrogen . Rotsare capable of making their own protein and other organ compounds . These activities by roots require energy of course . The proess  of respiration uses sugar to make the high energy compound ATP , which drives the biochemical reactions . Respiration also requires oxygen . Highly active roots require a good deal of oxygen .