HD is called an autosomal dominant disorder because only one copy of the defective gene, inherited from one parent, is necessary to produce the disease. The genetic defect responsible for HD is a small sequence of DNA on chromosome 4 in which several base pairs are repeated many, many times.
Carbon dioxide cannot pass through the protective waxy layer covering the leaf (cuticle), but it can enter the leaf through an opening (the stoma; plural = stomata; Greek for hole) flanked by two guard cells. Likewise, oxygen produced during photosynthesis can only pass out of the leaf through the opened stomata.
The equation for photosynthesis is below. Now if you look at the product side (to the right of the arrow), you will see that two things are produced in photosynthesis: Oxygen and Glucose. However, the oxygen that is produced in photosynthesis is released to the enviroment, leaving you with glucose. So, photosynthesis basically produces oxygen to release into the enviroment, and a carbohydrate (gives energy) for the plant. So to answer your question, the main product in photosynthesis is a carbohydrate. Hope this helps!