Colonies of algae-like single celled organisms called stromatolites
The earths atmosphere is made up of 78% nitrogen and 21% oxygen
It came from primitive organisms early in earth's history. They were the first organisms to use photosynthesis to make food, by using light to convert Carbon dioxide and water into glucose (food) and oxygen. Since oxygen is a waste product of photosynthesis, it was released into the air. As more and more of these organisms multiplied, large amounts of oxygen were released into the air, forming today's atmosphere.
oxygen
Oxygen makes up 21% of the Earths atmosphere.
mars has very thin atmosphere made mostly out of Carbon dioxide(about 95%) and almost no Oxygen (0.2%)
Earths atmosphere dose have oxygen in it, without it we would all be dead we require oxygen to breathe.
The earths atmosphere is made up of 78% nitrogen and 21% oxygen
The amount of oxygen in the atmosphere increased because the number of photosynthetic organisms, which release oxygen, on the earth dramatically increased. This lead to the Great Oxygenation Event, or the Oxygen Crisis, 2.4 billion years ago - when this free O2 entered the Earth's atmosphere.
no
97%
oxygen
yes
Animals remove oxygen from the atmosphere.
It came from primitive organisms early in earth's history. They were the first organisms to use photosynthesis to make food, by using light to convert Carbon dioxide and water into glucose (food) and oxygen. Since oxygen is a waste product of photosynthesis, it was released into the air. As more and more of these organisms multiplied, large amounts of oxygen were released into the air, forming today's atmosphere.
The Earths atmosphere protects the earth from meteors and it tgives us oxygen
Nitrogen makes up 78% of the earths atmosphere Oxygen makes up 21% of the earths atmosphere
Free oxygen