<span>Pleural sac is a two
layered membrane formed when a serous membrane known as pleura folds back onto
itself. Thus, the pleura invest the lungs and line the walls of the thoracic
cavity. However, the potential volume of the thoracic cavity increases during
inhalation.</span>
<span>Organic Chemistry is so important in the study of Biology because most reactions in Biology are organic reactions. Organic chemistry is the study of structure, properties, and reactions of organic compounds</span>
Answer:
The major levels of organization in the body, from the simplest to the most complex are: atoms, molecules, organelles, cells, tissues, organs, organ systems, and the human organism.
