Chemistry is important in biology because both sciences focus study on

Chemical reactions.

Explanation:

Chemistry is the study of different chemicals and their chemical reaction. Every day one uses the things all are made up of chemicals. All the chemicals and matters are the result of the chemical reaction.

For example, water is a compound which is formed by the hydrogen bond between the 2 hydrogens and one oxygen molecule. The properties of water are also different from individual hydrogen and oxygen molecules.

Our body is also made up of 70% to 80 % of water. All the metabolic reaction need water. Similarly, all matters are made up of chemicals. Chemical reactions happen when an organism eat, breathe, division of cell occur, etc. Every physiological process includes a chemical reaction.

The living organisms consist of some biomolecules, carbon, hydrogen, oxygen, nitrogen. All are playing a vital role in different biochemical reactions. Biochemistry is the branch of study in biology which deals with the role of chemistry in biology.  

Chemistry and biology are important for studying the different chemical reactions occur in the living organisms. Proteins, carbohydrates, lipids, are all formed due to the chemical reaction and these are known as biomolecules.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).