Totipotent cells can differentiate into more types of cells
The correct answer should be the Periderm.
It is not as simple as this, of course and you would be wise to know that periderm is just a part of the overall concept that is bark, because bark is not a biological term.
Claim: No tools to discover the impending Cell Theory.
Reasoning:
Schleiden and Schwann, as well as Virchow, are generally seen as the founders of the cell theory, due to their pioneering scientific work in the 1800s. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
Evidence: The cell theory has many complexities and is of importance due to its affect to nearly every aspect of biology, from our comprehension of life & death, managing diseases, cycles and etc. But early scientists had no tools to study cells. They didn't even know about them. It took the invention of the microscope to view them and to begin an understanding of cells.
(Two Dutch spectacle-makers and father-and-son team, Hans and Zacharias Janssen, create the first microscope.) Matthias Schleiden observed that all plants were made of cells from the microscope and Theodor Schwann observed that all animals were also made of cells. Rudolf Virchow observed that cells only come from other cells Virchow saw cells dividing and added that living cells arise only from other living cells. These ideas led to cell theory, which states that all organisms are made of cells, all life functions occur in cells, and all cells come from other cells.
If you are referring to selection pressure, when the selection pressure decreases, there will be weaker forces of natural selection. The angler fishes without the favourable traits would not be that strongly selected against and vice versa. In some cases such as predation selection pressure, the population of angler fishes in the habitat may increase
