oxygen and carbon dioxide are the 2 most important gases for living things
All living organisms are composed of one or more cells.
Water cycle is important for living organisms. It helps in recycling of water.
nitrogen
The gases of the environment are important to all living things because they help them in various processes. For instance animals need oxygen for respiration while the plants need carbon dioxide for photosynthesis.
Because it's the most primitive and universal pigment in living organisms.
Carbohydrates, lipids, proteins, and nucleic acids.
The most important parts of climate for most living things would be temperature and precipitation. This is because some organisms need water to live or a certain temperature.
While there are many more than two particular things that are essential to the survival of both humans and animals, I think that the answer you're searching for is water and oxygen. These two specific things are critical to the survival of nearly all living organisms (in one form or another).
liquid
Single celled organisms are examples of living cells that are organisms. Most other living cells are parts of living organisms, but could not survive long on their own.
If you ment A living organism, then no it isn't. But I'm sure you ment in living organisms. Then yes, it is an important element found in most organisms and is used for a great range of functions. One example would be pH regulation in the blood, or any other liquid.
The most important gases in air are oxygen, nitrogen, argon helium krypton