Answer:When a wound causes bleeding, the body responds with a positive feedback loop to clot the blood and stop blood loss. Substances released by the injured blood vessel wall begin the process of blood clotting
Explanation:
The atmosphere also protects living things on Earth from the sun's harmful ultraviolet radiation. A thin layer of gas called ozone high up in the atmosphere filters out these dangerous rays. The atmosphere also helps to sustain life of Earth.
There are actually two red pigments found in certain vertebrates that function in oxygen transport (or storage). Hemoglobin is present in the blood of most vertebrates and binds oxygen molecules, in order to transport them to body tissues in need of oxygen for energy (ATP) production.
Myoglobin, mainly in mammals, is a protein (enzyme) found in red (skeletal) muscle cells, that aids in binding oxygen when it's plentiful being delivered via blood. The purpose is that in high stress, low oxygen situations such as strenuous exercise, the myoglobin releases its bound oxygen to provide it to the starving overworked muscle cells.
**Fun fact: it's the hemoglobin that gives the bright red color of blood when it's bound to oxygen, and the myoglobin of mammal flesh gives it the typical pinkish-red hue that is seen in mammalian meat (veal, steak, ham, venison, bison, etc.). Other non-mammalian animals (fish, birds, frogs, snake, alligator, etc.) tend to have lighter-colored skeletal muscle meat due to the lack of myoglobin, amongst other factors.
Cells are the smallest unit of life
