Question

what does the modern cell theory propose

Answer 1

Old cell theory states:All plants and animals are made up of basic building structure called cells. Given by schleiden and schwann. Cell is the basic structure of life.
Modern cell theory states: All cells arise from pre existing cells by the process of cell division.

Answer 2

Modern cell theory proposes that each new cell arises from a pre-existing cell.

Explanation:

Whereas when we talk about the old cell theory this, the cells are the basic or the fundamental unit of life.

It is the building block of every living organism may it be a uni or a multicellular cell.