In the history of cell biology, who first coined the term protoplasm for the living substance inside cells?

Introduction / Context:
This question belongs to the history of biology and cell theory. It asks about the origin of the term protoplasm, which was historically used to describe the living contents of a cell. Knowing the names and contributions of early scientists helps you appreciate how modern cell biology developed over time.

Given Data / Assumptions:

• The question asks specifically who coined the term protoplasm.
• Several scientists from the nineteenth century are listed in the options.
• It is assumed that you are familiar with key figures in early cell biology.

Concept / Approach:
Protoplasm was an important concept in early cell theory. It refers to the living material inside a cell, including cytoplasm and nucleus, before more detailed structures were understood. The term was first introduced by the Czech physiologist Jan Evangelista Purkinje in the nineteenth century when he used it to describe the contents of animal cells. Later, Hugo von Mohl applied the term protoplasm specifically to the living substance of plant cells, helping to popularise it. However, the origin of the term is credited to Purkinje. Oken and Kolliker were important biologists but not the ones who first coined this specific term.

Step-by-Step Solution:

Verification / Alternative check:
If you consult historical summaries of cell theory in standard botany or zoology textbooks, they usually state that Purkinje first used the term protoplasm in 1839 to describe the living substance of cells. Later, von Mohl applied the term to plant cell contents in 1846. This sequence of events is consistently repeated across reputable sources, confirming that Purkinje has priority in coining the term.

Why Other Options Are Wrong:

Hugo von Mohl is incorrect in this context because, although he played an important role in characterising protoplasm in plant cells, he was not the first to coin the term.

Oken is incorrect because his contributions lie in broader natural philosophy and early ideas about organisms, not specifically in naming the living matter inside cells.

Kolliker is incorrect because he is known for work in embryology and histology, but not for introducing the term protoplasm.

Common Pitfalls:
Students often confuse the scientist who first coined a term with the person who later popularised or clarified it. Because Hugo von Mohl is frequently mentioned in discussions of plant cell protoplasm, some learners mistakenly attribute the original term to him. Another pitfall is to guess based solely on which name looks familiar without recalling their specific contributions. Carefully reading historical notes and timelines in textbooks helps avoid these mix ups.

Final Answer:
The scientist who first coined the term protoplasm for the living substance inside cells was J. E. Purkinje.