To warm up before a run, david begins by completing quad and hurdler's stretches. which of these accurately evaluates his choice of warm-up activities? these activities are appropriate because they prepare muscles for intense movement. these activities are not appropriate because the muscles stretched are not warm yet. these activities are appropriate because they make the leg muscles more flexible. these activities are not appropriate because they stretch muscles not used in the exercise. you must check the box below prior to submitting your exam!

You isolate an infectious substance capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. you have four methods at your disposal to analyze the substance and determine the nature of the infectious agent.i. treat the substance with enzymes that destroy all nucleic acids and then determine whether the substance is still infectious.ii. microscope.iii. culture the substance on nutritive medium, away from any plant cells.iv. treat the sample with proteases that digest all proteins and then determining whether the substance is still infectious.if you already know that the infectious agent was either bacterial or viral, which method(s) listed above would allow you to distinguish between these two possibilities? a) ib) iic) ii or iiid) iv