Answer:
The oxygen and carbon dioxide in the lower layers of the troposphere (that touches Earth) allow life to exist as organisms can respire and plants can photosynthesise. The atmosphere also helps to keep the Earth warm by trapping solar energy.
Explanation:
Oxygen is released during photosynthesis during the light phase of photosynthesis.
Rather, physicists believe the Big Bang created and stretched space itself, expanding the universe. As the early universe cooled, the matter produced in the Big Bang gathered into stars and galaxies. For a brief moment after the Big Bang, the immense heat created conditions unlike any conditions astrophysicists see in the universe today.
In the Human body which system functions in detecting and responding to Stimuli is called the Nervous System.
But an egg or sperm only has one. That one is chosen at random, through a process called meiosis. When meiosis messes up, you can end up with to many or too few chromosomes. One extra chromosome in a egg or sperm means three in the fertilized egg and so trisomy.