Oxygen is $not$ produced during photosynthesis by

The most vital process for the existence of life on earth is

Which of the following photosynthetic bacteria have both $PS-I$ and $PS-II$?

In which of the following is the rate of transpiration highest?

Select the correct option:
$(1)$ Julius von Sachs / $T$. $W$. Engelmann proved with evidence that glucose is produced when plants grow.
$(2)$ In $PS-II$,maximum light absorption occurs at a wavelength of $680 \, nm / 800 \, nm$.

Assertion $:-$ There is not a complete one-to-one overlap between the absorption spectrum of chlorophyll $a$ and the action spectrum of photosynthesis.
Reason $:$ Most of the photosynthesis takes place in the blue and red regions of the spectrum,but some photosynthesis does take place at the other wavelengths of the visible spectrum.