Here's what happens: 1  The receptors, which are nerve endings in your nasal passageways, detect an irritant. 2  Nerves carry these impulses to the sneezing center in your brain stem. 3  The sneezing center sends its instructions along your facial nerve and the nerves that lead to your lungs and diaphragm. 4  Your eyes start to water, and your nasal ...
TOP. THE MAIN EVENTS OF PHOTOSYNTHESIS (higher level). Photosynthesis takes place in two stages; the light stage and the dark stage. The light stage needs light so it is called the light-dependent stage. The dark stage is called the light-independent stage. TOP. THE LIGHT STAGE. The light stage takes place in the chloroplast s thylakoid membranes. The events of the light stage are as follows: 1. Light Absorption: All the colours of white light (except green light) are absorbed by pigments in the chloroplast.
The energy absorbed in the light reactions is used to drive this process, with the end result being sugar molecules with energy stored in the carbon-carbon bonds of the sugar. The 3 types of photosynthesis differ in details of how these processes are carried out. Normal: photosynthesis is carried out by most plants growing in areas with sufficient water. In this type of photosynthesis, an enzyme called RuBP carboxylase grabs CO 2 in one of the first steps of photosynthesis.