Discovery of the Cell and Cell Theory Questions in English

(N/A) The cell was discovered by $Robert \ Hooke$ in $1665$ using a self-designed microscope.
He examined a thin slice of cork under the microscope.
He observed that the cork resembled the structure of a honeycomb,consisting of many small,box-like compartments which he termed as 'cells'.

(N/A) The cell is considered the structural unit of life because all living organisms are composed of cells,which provide the basic framework and organization for the body.
It is called the functional unit of life because all metabolic activities and physiological processes necessary for survival,such as respiration,protein synthesis,and waste excretion,occur within the cell.
These activities are carried out by specialized structures known as cell organelles,which perform specific tasks like energy production,transportation,and synthesis of materials.
Therefore,the cell is the smallest unit capable of performing all life processes independently.

(N/A) $(i)$ Osmosis is the process responsible for the gathering of water in the hollowed portion of $B$ and $C$. Since the concentration of solute (sugar in cup $B$ and salt in cup $C$) is higher inside the cup as compared to the water outside,water moves from its higher concentration (outside the cup) towards the lower concentration (inside the cup) through the semipermeable membrane of the potato cells. This process of inward movement of solvent is called endosmosis.
$(ii)$ Potato $A$ acts as a control for the experiment. It is necessary to provide a baseline for comparing the results and to demonstrate that the movement of water is due to the concentration gradient of the solute.
$(iii)$ Water does not gather in the hollowed portions of $A$ and $D$ because:
In potato $A$,the hollowed portion is empty. Since there is no concentration difference (no solute),no osmosis occurs.
In potato $D$,although it contains sugar,it is boiled. Boiling kills the potato cells and destroys the semipermeable membrane,which is essential for osmosis to occur. Therefore,no water movement takes place.

(B) The concept that 'all cells arise from pre-existing cells' was proposed by Rudolf Virchow in $1855$. This statement,known as 'Omnis cellula-e cellula',provided a significant addition to the cell theory originally proposed by Schleiden and Schwann,which did not explain how new cells were formed.

(C) The cell theory was proposed by Matthias Schleiden and Theodor Schwann in $1838$ and $1839$ respectively.
They stated that all plants and animals are composed of cells and that the cell is the basic unit of life.

(D) Robert Hooke was the first to observe cells in $1665$,but he observed dead cells from a cork slice.
It was Antonie van Leeuwenhoek who,with the help of an improved microscope,was the first to observe and describe free-living cells such as bacteria and protozoa in pond water.

(N/A) Yes,$I$ agree with the statement that '$A$ cell is a building unit of an organism'.
This is because all living organisms are composed of cells,which are the fundamental structural and functional units of life.
Just as bricks are the building blocks of a building,cells are the basic units that organize to form tissues,organs,and organ systems,ultimately constituting the entire organism.
Furthermore,a cell is the smallest independent unit capable of performing all essential life processes,such as metabolism,growth,and reproduction.

(A) Robert Hooke examined a thin slice of cork under a primitive microscope. He observed that the cork resembled the structure of a honeycomb consisting of many little compartments. He named these compartments '$cells$'.

(A) The cell was first observed by Robert Hooke in $1665$. He examined a thin slice of cork under a primitive microscope and observed that it consisted of many small,box-like compartments,which he termed 'cells'.

(N/A) cell is defined as the basic structural,functional,and biological unit of all living organisms.
In Latin,the word 'cellula' means 'a little room'.

(N/A) Yes, $I$ agree that a cell is the building unit of an organism.
$1$. Structural Basis: Just as bricks are the building blocks of a building, cells are the fundamental structural units of all living organisms.
$2$. Functional Basis: All life processes, such as metabolism, respiration, and reproduction, occur at the cellular level.
$3$. Organization: Cells organize to form tissues, which form organs, organ systems, and finally the complete organism. Therefore, the cell is the basic unit of life.

(N/A) The scientist who discovered cells is $Robert \ Hooke$ in the year $1665$.
Two examples of single-celled (unicellular) organisms are:
$(i)$ $Amoeba$
$(ii)$ $Paramecium$

(N/A) The cell theory states that:
$(i)$ All living organisms are composed of cells and products of cells.
$(ii)$ All cells arise from pre-existing cells.
The cell theory was originally proposed by Matthias Schleiden $(1838)$ and Theodor Schwann $(1839)$.
Later,Rudolf Virchow $(1855)$ expanded the theory by suggesting that all cells arise from pre-existing cells (Omnis cellula-e cellula).

(N/A) The invention of the microscope by $Antony$ $van$ $Leeuwenhoek$ led to the discovery of the microscopic world.
$(b)$ $Amoeba$ is a single cell that constitutes a whole organism. Such organisms are called unicellular organisms.
$(c)$ Every multicellular organism begins its life as a single cell called the zygote. This zygote is formed by the fusion of male and female gametes during fertilisation. Through repeated cell divisions,this single cell develops into a complex multicellular organism.

(N/A) $(i)$ The fundamental unit of life is the cell.
$(ii)$ The cell was first discovered by Robert Hooke in $1665$.
$(iii)$ Cells are generally observed under a microscope because they are microscopic in size. However, some cells are large enough to be seen with the naked eye, for example, an ostrich egg.

(A) Anton van Leeuwenhoek was the first person to observe and describe living cells,such as bacteria,protozoa,and spermatozoa,using a simple microscope in $1674$.
Robert Hooke discovered dead cells in a cork slice in $1665$.
Purkinje coined the term 'protoplasm'.
Robert Brown discovered the nucleus in the cell.

(B) The concept that new cells arise from pre-existing cells, known as "Omnis cellula-e cellula", was proposed by Rudolf Virchow in $1855$.
This statement expanded the cell theory originally proposed by Schleiden and Schwann, which did not explain how new cells were formed.
Therefore, the correct answer is $B$ (Virchow).

(B) The cell theory was formulated by $M.J. Schleiden$ and $Theodor Schwann$ in $1838$ and $1839$, respectively.
$M.J. Schleiden$, a German botanist, observed that all plants are composed of different kinds of cells which form the tissues of the plant.
$Theodor Schwann$, a British zoologist, reported that cells had a thin outer layer which is today known as the '$plasma membrane$'.
Together, they proposed the cell theory, which states that all living organisms are composed of cells and products of cells.