1. Why is DNA extracted from biological samples?

Well Basically if you and your family members are biological meaning related to each other it would make sense to take samples from them. And also in families there is always someone who inherit looks and the same blood like for example you may look like your dad and have the same blood type as him.     ;) your welcome

The ability to extract DNA is of primary importance to studying the genetic causes of disease and for the development of diagnostics and drugs.

Explanation:

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

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