Question

the study of which structure was instrumental in the formulation of the modern cell theory? plant cell animal cell cell membrane dna molecule

Explanation:

The modern cell theory emphasizes that cells contain DNA which is passed from cell to cell during cell division. The study of the DNA molecule was crucial as it provided insights into the genetic material that is fundamental to the functioning and inheritance in cells. Plant cells, animal cells, and cell membranes were studied earlier but the discovery and study of DNA (molecule) added a key molecular - genetic aspect to the modern cell theory.

Answer:

DNA molecule