Answer:
1. Asexual Reproduction (If there is only one organism reproducing)
2. Selective Breeding
Explanation:
1. If there is only one parent organism that means the offspring it is a carbon copy of its parent.
2. Selective breeding is breeding to bring out more desirable traits out of the species, like how dog breeders breed for better sense of smell or hearing.
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.
Yes, it’s main function is to protect the organisms from germs, bacteria etc... and cover the essential organs from these organisms too.