Nathan is conducting streak plate technique as described in the investigation. As he completes the activity, note any parts of his technique that should be corrected and explain why the correction is necessary/important.

Nathan mixes the two cultures of bacteria into an empty sterile culture tube, and gently taps the tube to mix. He takes the lid off an agar plate and sets it on the counter, then with a loop of broth from the mixed culture, inoculates a quarter of the agar surface using a zig-zag pattern. Next, using the same loop, he pulls some inoculum from the first sector of the agar into the adjacent sector using a zig-zag pattern. He follows this same procedure to pull inoculum from the second sector into an adjacent one, and from the new third sector into the last adjacent one. He pulls the loop through some of the first sector as he completes this last zig-zag pattern. Nathan finally replaces the lid on the agar plate, then turns it upside down for labeling and incubation.