Question

What could be represented by this when written in a hierarchical order--- cell, tissue, organ, etc. ?

Answer 1

These are various levels of organisation.

Muscle fibre (=cell) `rarr`Cardiac muscle (=tissue) `rarr`Heart (=organ)

Explanation:

Unit of life is cell. A group of cells performing a particular function form tissue. Various tissues integrate together in an organ. Functionally related organs form an organ system. There are different organ systems in an organism.