How can biology be studied at different scales or levels

The different levels of biology are described below.

Explanation:

Biology can be studied at different levels from a single cell to the entire biosphere. The ladder from a single cell to the biosphere is known as the biological level of organization.

Following are the levels of organization:

A cell comprises of different organelles and is the main unit of life. For e.g bone cells

Tissues:

The cells combine to make tissues. For e.g the connective tissue

Organs:

Different tissue work together to make an organ. For e.g stomach

Organ system :

Different organs work together to make an organ system.  For e.g The circulatory system contains heart and the blood vessels.

Organism:

Organ systems combine to make an organism. for e.g any human

Population

Group of organisms of the same species. For e.g a group of humans

Community

The different populations present in an area. For e.g all the plants, animals and microbes in an area.

Ecosystem

All the biotic as well as abiotic factors in an area make the ecosystem.

Biome

Different communities that can exist in the same climate.

Biosphere

Biosphere is all the life that exists on the planet earth and also all the abiotic factors present on earth.

the answer is:

carbon dioxide