Question

1. Plants can carry out both photosynthesis and respiration ____ (at the same time).

2. The primary substance we used to determine the presence or absence of CO2​ is ___.



3. When CO2​ levels decrease, the pH of the water ______ (increases/decreases).

Answer 1

1. simultaneously (they can photosynthesize and respire at the same time).

2. bromothymol blue (BTB, a pH indicator used to detect CO2 levels).

3. increases — less dissolved CO2 means less carbonic acid, so the water becomes less acidic (higher pH).