Cell Organelles Questions in English

(A) Lysosomes are membrane-bound vesicular structures formed by the process of packaging in the Golgi apparatus.
These vesicles contain hydrolytic enzymes (hydrolases like lipases,proteases,and carbohydrases) that are synthesized in the rough endoplasmic reticulum and then transported to the Golgi apparatus for modification and packaging into lysosomes.

(C) The $Smooth$ $Endoplasmic$ $Reticulum$ $(SER)$ is the cell organelle responsible for the detoxification of many poisons and drugs.
In liver cells of vertebrates,$SER$ plays a crucial role in detoxifying a wide range of toxins and drugs,making them more water-soluble and easier for the body to excrete.

(D) The $Rough$ $Endoplasmic$ $Reticulum$ $(RER)$ is responsible for the synthesis of proteins because it has ribosomes attached to its surface.
$Smooth$ $Endoplasmic$ $Reticulum$ $(SER)$ is responsible for the synthesis of lipids (fats).
These proteins and lipids are essential for building the cell membrane,a process known as membrane biogenesis.
Therefore,the correct answer is $Rough$ $Endoplasmic$ $Reticulum$ (considering the primary site of protein synthesis and the overall role of the $ER$ system).

(B) The $Golgi$ $apparatus$ is the cell organelle responsible for the modification, packaging, and secretion of proteins and lipids.
One of its primary functions is the synthesis of complex sugars from simple sugars.
It also plays a crucial role in the formation of lysosomes.

(C) Vacuoles are membrane-bound organelles found in the cells of plants,fungi,and some protists,animals,and bacteria.
Their primary functions include:
$1$. Storage: They store nutrients,water,and various substances.
$2$. Turgidity and Rigidity: In plant cells,the large central vacuole maintains turgor pressure,which provides structural support and rigidity to the cell.
$3$. Waste Excretion: They help in the removal of waste products from the cell.
Locomotion is not a function of the vacuole. Locomotion in cells is typically facilitated by structures like cilia,flagella,or pseudopodia.

(B) Plastids are organelles found in plant cells that are classified based on the pigments they contain:
$1$. Chromoplasts: These are coloured plastids (containing pigments like carotenoids) that provide yellow,orange,or red colours to various plant parts.
$2$. Chloroplasts: These are green-coloured plastids containing chlorophyll,which is essential for photosynthesis.
$3$. Leucoplasts: These are colourless plastids primarily involved in the storage of nutrients like starch,oils,and proteins.
Therefore,the sequence for coloured,green,and colourless plastids is Chromoplasts,Chloroplasts,and Leucoplasts respectively.

(A) Camillo Golgi discovered the Golgi apparatus in $1898$. He used a technique called 'black reaction' to stain the nerve cells and other cells. This technique involves the use of silver nitrate solution,which helps in visualizing the structure of the Golgi apparatus under a microscope. Therefore,silver nitrate solution is specifically used to study the Golgi apparatus.

(B) Mitochondria and chloroplasts are unique cell organelles because they possess their own $DNA$ and ribosomes.
This allows them to synthesize some of their own proteins,a phenomenon known as semi-autonomous nature.
Since the nucleus is the primary site of $DNA$ in a cell,mitochondria are the organelles other than the nucleus that contain $DNA$.

(C) The $Chloroplast$ is known as the 'kitchen of the cell'.
This is because chloroplasts contain the green pigment $Chlorophyll$, which is essential for the process of $Photosynthesis$.
Through $Photosynthesis$, plants synthesize their own food (glucose) using sunlight, water, and carbon dioxide, similar to how a kitchen is used to prepare food.

(D) The $Smooth$ $Endoplasmic$ $Reticulum$ $(SER)$ is responsible for the synthesis of lipids, including steroids and phospholipids, which are essential for the formation of the cell membrane.
In contrast, the $Rough$ $Endoplasmic$ $Reticulum$ $(RER)$ is primarily involved in protein synthesis due to the presence of ribosomes on its surface.
Therefore, the correct option is $D$.

(C) Prokaryotic cells are characterized by the absence of membrane-bound organelles such as mitochondria,plastids,and lysosomes.
Ribosomes are the only organelles present in prokaryotic cells.
These ribosomes are of the $70S$ type,which are smaller than the $80S$ ribosomes found in eukaryotic cells.
They are not membrane-bound,which allows them to exist in the cytoplasm of prokaryotes.

(D) The $Ribosome$ is a non-membrane-bound organelle found in both prokaryotic and eukaryotic cells.
It is primarily composed of $RNA$ and proteins.
In contrast, the $Nucleus$, $Chloroplast$, and $Golgi$ $apparatus$ are all membrane-bound organelles.

(FALSE) The statement is False.
Plastids are specialized organelles found exclusively in plant cells and some algae.
They are responsible for processes like photosynthesis (chloroplasts) and the storage of starch or pigments (leucoplasts and chromoplasts).
Animal cells do not contain plastids.

(TRUE) True.
In many unicellular organisms like $Amoeba$,food particles are engulfed through the process of phagocytosis,forming food vacuoles. These vacuoles contain the consumed food,which is then digested by enzymes.

(TRUE) The statement is True.
The nucleus contains the genetic material $(DNA)$ of the cell. During cellular reproduction (cell division),the nucleus coordinates the replication of this genetic material and ensures its equal distribution into the daughter cells,thereby playing a central and essential role in the process.

(TRUE) True.
The endoplasmic reticulum $(ER)$ is a large network of membrane-bound tubes and sheets. It looks like long tubules or round or oblong bags (vesicles). The $ER$ membrane is similar in structure to the plasma membrane. There are two types of $ER$: Rough Endoplasmic Reticulum $(RER)$ and Smooth Endoplasmic Reticulum $(SER)$.

(FALSE) The statement is False.
$RER$ stands for Rough Endoplasmic Reticulum.
It appears 'rough' under a microscope specifically because it has ribosomes attached to its surface.
In contrast,the Smooth Endoplasmic Reticulum $(SER)$ lacks ribosomes,which is why it appears smooth.

(FALSE) The statement is False.
Explanation:
$1$. Plastids are classified into three types based on the type of pigments they contain: Chloroplasts,Chromoplasts,and Leucoplasts.
$2$. Chloroplasts contain chlorophyll and are green in color.
$3$. Chromoplasts contain carotenoids and are colored (red,yellow,or orange).
$4$. Leucoplasts are colorless plastids in which materials such as starch,oils,and protein granules are stored.

(TRUE) True.
Vacuoles are membrane-bound organelles that function as storage sacs for solid or liquid contents, such as water, nutrients, and waste products, particularly in plant cells where they can occupy up to $90\%$ of the cell volume.

(FALSE) The statement is False. Mitochondria are double-membrane-bound organelles. They consist of an outer membrane and an inner membrane,with the inner membrane folded into structures called cristae.