The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
Pieces of genes can be inserted into the genetic material of prokaryotes so that they will make the protein products encoded in the genes or copies of the genes themselves
As you workout your heart rate will increase because you need oxygen.
<span>Trophic level—90% of energy consumed at trophic
level is used by the consumer for survival and reproduction. The remaining 10%
is transferred to the next trophic level. So the answer is 10,000 x 0.9
or 9,000 calories will be generally available
to primary consumer</span>
