What instrument would a scientist use to take measurements in the upper troposphere

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?

Which type of respiration takes place when there is no oxygen present