4. What is the stroma of a chloroplast? What happens there?

Stroma, in botany, refers to the colorless fluid surrounding the grana within the chloroplast. Within the stroma are grana (stacks of thylakoid), and the sub-organelles or daughter cells, where photosynthesis is commenced before the chemical changes are completed in the stroma.The stroma is essential for this because not only does it contain the enzymes necessary for carbon fixation, it also manages the chloroplast response to cellular stresses and signaling between various organelles. It plays an important role in both the light-dependent and light-independent reactions of photosynthesis

i believe you meant to say air rather than hair so the answer is below ")

the dead sea, the lowest place on earth at 430 metres (1,410 ft) below sea level, has a correspondingly high typical atmospheric pressure of 1065 hpa.