Question

Which of the following is not correct?
A. Robert Brown discovered a cell.
B. Schleiden and Schwann formulated the cell theory.
C. Virchow explained that cells are formed from pre-existing cells.
D. A unicellular organism carries out its life activities within a single cell.

Answer 1

Hint: The perfect and very simple definition of cell is that a cell is a basic structural, functional and biological unit of life. The cell is the Latin word that actually means “small room”. A cell is the smallest unit of life.

Complete answer:
The cell theory was a universally accepted theory in biology. A cell is the structural, functional and biological unit of life along with this it is also the reproductive unit too. The two scientists who formulated cell theory were Matthias Jakob Schleiden and Theodor Schwann. This concept of cell was brought forward in 1839.
Rudolf Virchow in 1985 was the first scientist to explain that cells arise from pre-existing cells. By carefully observing the process of cell division. He argued that cells only arose from the division of pre-existing cells.
It is the true statement that a single cell carries out all the functions in a unicellular organism.
The scientist named Robert Hooke was the first to discover the cell in 1665.

Hence, the correct answer is option (A)

Note: The four main type of cells are as follows:
1. epithelial cell
2. nerve cells
3. muscle cells
4. connective tissue cell
All living things are made up of cells.