When tissues are dissociated into single cells, they will segregate to reflect their final position within the developing embryo. This phenomenon is due to the activity of:

Astudent poured a solution of bromothymol blue indicator into three test tubes. then he placed an aquatic plant in two of the test tubes, as shown below. he placed a stopper on each test tube and placed them all in the dark for 24 hours. bromothymol blue turns from blue to yellow in the presence of co2