THE CELL
CELL THEORY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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All cells have a cell wall.
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All cells come from pre-existing cells.
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All cells are capable of photosynthesis.
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All cells can develop into any other type of cell.
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Detailed explanation-1: -In 1839 anatomist Theodor Schwann proposed that all animals are composed of cells. In 1855 biologist Rudolph Vichow added to Schleiden’s and Schwann’s observations and proposed that all living things are composed of cells. Which statement is also part of Virchow’s cell theory ? All cell have a cell wall.
Detailed explanation-2: -In 1838 Schleiden defined the cell as the basic unit of plant structure, and a year later Schwann defined the cell as the basic unit of animal structure. Schleiden and Schwann articulated their observations as a unified theory-the cell theory-in 1839.
Detailed explanation-3: -In 1838, Matthias Schleiden, a German botanist, concluded that all plant tissues are composed of cells and that an embryonic plant arose from a single cell. He declared that the cell is the basic building block of all plant matter.
Detailed explanation-4: -By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. 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.
Detailed explanation-5: -Schleiden and Schwann, who are usually given credit for elucidating the cell theory, made their marks in 1838 and 1839. In 1838 Matthais Schleiden (1804–1881) proposed that every structural element of plants is composed of cells or the products of cells.