Answer: A scientific hypothesis is the initial building block in the scientific method. Many describe it as an "educated guess," based on prior knowledge and observation. While this is true, the definition can be expanded. A hypothesis also includes an explanation of why the guess may be correct
<span>Sterilization of animals reduces the level of circulating reproductive hormones leading to increased longevity, typically due to reduce cancer mortality. The primary aim of animal sterilization is avoiding overpopulation, but this increased longevity could be an added benefit for an individual animal.</span>
The lower limb bones are attached to the axial skeleton by a ring of bones called the pelvic girdle. The pelvic girdle consists of the right and left hip bones.
The bones of the head and trunk of the vertebrate form the axial skeleton.
These alveoli are the smallest types of lung tissue, and one of the most important. In addition to being the primary means by which oxygen enters and carbon dioxide escapes the bloodstream, these small pouches of air are also the reason why the lungs do not totally collapse when a person breathes out. This is because they contain a cell that secretes a special chemical to lower the surface temperature to prevent lung collapse. The alveoli also contain other cells that secrete chemicals to attack and remove any foreign objects in the lungs, such as dust, dirt and other debris.
In addition to making up alveolar sacs, alveoli also form alveolar ducts. It is estimated that there are more than 300 million alveoli in the human lungs, all of which are located in either alveolar ducts or sacs that are found at the end of the smaller passageways, or bronchioles, in the lungs.
SHORT ANSWER:
Alveolar sacs contain tiny pouches called alveoli, whose primary function is gas diffusion. These clusters of alveoli have thin walls that allow oxygen to pass easily from the lungs into the bloodstream and carbon dioxide to flow from the blood to the lungs so it can exit the body.
