By their texture :) hope it helps
competition plays a very important role in ecology and evolution. The best competitors are the ones who survive and get to pass on their genes.
Most peripheral nerves are nerves outside the brain and the spinal cord, carrying both sensory and motor impulses. The peripheral nervous system is one of the two components of the nervous system, the other part is the central nervous system. Peripheral nerves are classified into motor, sensory and autonomic nerves.
Offspring with a 3:1 ratio suggest that both parent that both parent that give rise to this offspring were both heterozygous. Heterozygous individual is someone who has two different allele at a locus whereby by one gene is dominant over the other gene. example of heterozygous parent is a parent Aa pair of alleles. In this pair gene A is dominant over gene a
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.
