Answer:
to study the genetic causes of disease and for the development of diagnostics and drugs.
Explanation:
It is important to extract DNA from a cell in order to study the genetic causes of disease and for the development of diagnostic and drugs. Scientists will use a cell culture system, which is cells from an organism that have either been made to continuously proliferate (grow) or are cancerous in nature (from cancer).
These cells allow us to continue working on experiments where we can change the conditions to determine various cell functions.