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.
During this process of sugar production, carbon dioxide combines with water to. form glucose and oxygen is released. Oxygen that is produced in photosynthesis. is given off as a gas. If a lot of oxygen is being given off, photosynthesis is. occurring rapidly. If little oxygen is being given off, photosynthesis is. occurring slowly. The amount of trapped light energy and the amount of carbon. dioxide available affects the rate of photosynthesis. The purpose of adding sodium bicarbonate powder to the water increases the. amount of carbon dioxide in the water.