Why is the apparatus left for 15 minutes at each new light intensity before starting measurements

The apparatus is the instrument to perform various experiments in the lab. The apparatus is usually made up of glass.

These are the following apparatus used in the lab:-

Test

Apparatus left for 15 minutes at each new light intensity before starting measurements to sterilize and make it pure and get the error-free readings.

Different light intensities are sensitive to the various bacteria and help to kill them.

For more information, refer to the link:-

link

In all cells, all the time

Even though plants carry out photosynthesis to produce energy and "food," their cells would still need to undergo cellular respiration, as with all other living cells. Cellular respiration occurs in the mitochondria of cells and produces ATP (energy) in the process. This ATP is then used by the plants in all its other processes.