Cell Organelles Questions in English

(B) Plastids,specifically chloroplasts,contain pigments like chlorophyll that can trap solar energy.
This trapped energy is used to convert inorganic raw materials into chemical energy in the form of food,known as glucose,through the process of photosynthesis.
Since they are responsible for the production of food for the cell,they are referred to as the 'kitchens of the cell'.

(N/A) The endoplasmic reticulum $(ER)$ is called the transporting channel of the cell because it serves as a network of membranes that facilitates the transport of materials,particularly proteins and lipids,between various regions of the cytoplasm or between the cytoplasm and the nucleus.

(C) The plastid that stores starch,oils,and protein granules is known as the $Leucoplast$.
$Leucoplasts$ are primarily storage plastids that lack pigments.
Depending on the type of nutrient stored,they are further classified as $Amyloplasts$ (for starch),$Elaioplasts$ (for oils/fats),and $Aleuroplasts$ (for proteins).

(N/A) Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid $(DNA)$. The primary function of chromosomes is to carry genetic information from one generation to the next in the form of genes. They play a crucial role in cell division,heredity,variation,and evolutionary processes by ensuring that $DNA$ is accurately replicated and distributed to daughter cells.

(A) The cell organelle associated with the elimination of old and worn-out cells is the $Lysosome$.
$Lysosomes$ contain powerful digestive enzymes capable of breaking down all organic material.
When a cell gets damaged or old, $lysosomes$ may burst, and the enzymes digest their own cell, which is why they are often referred to as the '$suicide \text{ bags}$' of the cell.

(B) The $Endoplasmic \text{ } Reticulum$ $(ER)$ is the cell organelle responsible for intracellular transport. It forms a network of membrane-bound tubules and vesicles that act as a transport system for materials, particularly proteins and lipids, between various regions of the cytoplasm.

(B) Lysosomes are known as 'digestive bags' because they contain powerful digestive enzymes (hydrolytic enzymes) synthesized by the Rough Endoplasmic Reticulum $(RER)$. These enzymes are capable of breaking down all types of organic material,including worn-out cell organelles,foreign substances,and food particles,through the process of intracellular digestion.

(A) The Golgi apparatus was discovered by Camillo Golgi in $1898$.
Structure: It consists of a system of membrane-bound vesicles arranged approximately parallel to each other in stacks called cisternae. These membranes often have connections with the membranes of the endoplasmic reticulum $(ER)$.
Functions: The primary function of the Golgi apparatus is the packaging and dispatching of materials synthesized in the cell to various targets inside and outside the cell. It is also involved in the formation of lysosomes and the synthesis of complex sugars from simple sugars.

(N/A) The components of the cell are known as cell organelles. Each organelle performs a specific function such as protein synthesis,waste disposal,or energy production.
$(b)$ The energy currency of the cell is Adenosine Triphosphate $(ATP)$. It is produced in the mitochondria during cellular respiration and provides energy for various metabolic activities.

(N/A) $(i)$ Mitochondria are bounded by a double membrane structure.
$(ii)$ The outer membrane is porous and allows the passage of various molecules.
$(iii)$ The inner membrane is deeply folded into structures called cristae.
$(iv)$ These folds significantly increase the surface area for $ATP$ generating chemical reactions.

(N/A)

$SER$ (Smooth Endoplasmic Reticulum)	$RER$ (Rough Endoplasmic Reticulum)
$1$. Ribosomes are absent on the surface.	$1$. Ribosomes are present on the surface.
$2$. It is primarily involved in lipid synthesis.	$2$. It is primarily involved in protein synthesis.

(N/A) $Mitochondria$: Site of $ATP$ generating reactions.
$Chloroplasts$: Site of photosynthesis.

(N/A) $(i)$ Lysosomes contain powerful digestive enzymes known as hydrolytic enzymes.
$(ii)$ These enzymes are capable of breaking down all organic materials. Thus, they help to keep the cell clean by digesting foreign materials as well as worn-out cell organelles.
$(iii)$ The Rough Endoplasmic Reticulum $(RER)$ is responsible for manufacturing these enzymes.

(N/A)

Vacuoles in Plant Cell	Vacuoles in Animal Cell
$1$. Vacuoles are very large and few in number.	$1$. Vacuoles are small-sized and more in number.
$2$. Vacuoles are full of cell sap and provide turgidity and rigidity to the cell.	$2$. Vacuoles may contain food items and are called food vacuoles. In some organisms such as $Amoeba$,vacuoles become specialized to expel excess water and waste products from the cell.

(A) Mitochondria are referred to as 'strange organelles' because they possess their own $DNA$ and ribosomes.
This unique feature allows them to synthesize some of their own proteins independently.
Due to this capability,they are considered semi-autonomous organelles.

(N/A) $(i)$ The energy currency of the cell is $ATP$ (Adenosine Triphosphate).
$(ii)$ The cell organelle that releases this energy is the Mitochondria,which is often referred to as the 'powerhouse of the cell'.

(N/A) The two chemicals present in living organisms composed primarily of carbon,hydrogen,and oxygen are Carbohydrates and Fats.
$1$. Carbohydrates: They serve as the primary source of energy for the body,providing fuel for cellular activities.
$2$. Fats: They act as a concentrated source of energy and are essential for storing energy,insulating the body,and protecting vital organs.

(N/A) The four essential carbon-containing molecules for life forms are:
$1$. $Proteins$: These are polymers of amino acids and are essential for structural and functional roles in cells.
$2$. $Carbohydrates$: These serve as the primary source of energy for living organisms.
$3$. $Fats$ $(Lipids)$: These are crucial for energy storage and the formation of cell membranes.
$4$. $Nucleic$ $acids$ ($DNA$ and $RNA$): These are responsible for the storage and transmission of genetic information.

(N/A) If there were no Golgi apparatus,the materials synthesized near the $ER$ would not be packaged,modified,stored,or transported to various targets inside and outside the cell. Furthermore,the formation of lysosomes would not take place,as they are produced by the Golgi apparatus.
$(b)$ The smooth endoplasmic reticulum $(SER)$ is the cell organelle responsible for detoxifying many poisons and drugs in the liver cells of vertebrates.

(B) Chromoplasts are coloured plastids that contain pigments like carotenoids,which provide yellow,orange,or red colours to plant parts.
Leucoplasts are white or colourless plastids primarily involved in the storage of nutrients like starch,oils,and proteins.
An example of a chromoplast that contains green pigment is the chloroplast,which contains chlorophyll.

(N/A) The two types of plastids are $Chloroplasts$ and $Leucoplasts$.
$1$. $Chloroplasts$: These contain pigments like chlorophyll and are responsible for performing photosynthesis in plants.
$2$. $Leucoplasts$: These are colourless plastids that primarily function in the storage of nutrients such as starch,oils,and protein granules.

(N/A) Nucleoid: In prokaryotic cells,the genetic material is not enclosed by a nuclear membrane. This undefined nuclear region containing only nucleic acids is known as the nucleoid.
$(b)$ Mitochondria: These are known as the powerhouses of the cell because they generate most of the cell's supply of adenosine triphosphate $(ATP)$,which is used as a source of chemical energy.

(N/A) $(i)$ Lysosomes contain powerful digestive enzymes capable of breaking down all organic material.
$(ii)$ During the disturbance in cellular metabolism,i.e.,when the cell gets damaged,lysosomes may burst and the enzymes digest their own cell.

(N/A) $(i)$ $RER$: Rough Endoplasmic Reticulum
$(ii)$ $SER$: Smooth Endoplasmic Reticulum
$(iii)$ $DNA$: Deoxyribonucleic Acid
$(iv)$ $RNA$: Ribonucleic Acid
$(v)$ $ATP$: Adenosine Triphosphate
$(vi)$ $SPM$: Selectively Permeable Membrane

(N/A) $(i)$ Oxidation of food takes place in mitochondria,and they release energy in the form of $ATP$. This energy is required for various chemical activities essential for life. Hence,mitochondria are known as the powerhouse of the cell.
$(ii)$ Plastids contain their own $DNA$ and ribosomes. Therefore,they are capable of synthesizing their own proteins.
$(iii)$ $A$ hypertonic solution has a lower water concentration than the cytoplasm of the cell. When a plant cell is placed in such a solution,water moves out of the cell due to the process of exosmosis,causing the cell to shrink.

(N/A) $(i)$ Rough endoplasmic reticulum is the site of protein synthesis.
$(ii)$ Golgi apparatus is involved in the storage,modification,and packaging of products in vesicles. It also synthesizes complex sugars from simple sugars and is involved in the formation of lysosomes.
$(iii)$ Lysosomes act as the waste disposal system of the cell by digesting foreign materials and worn-out cell organelles.
$(iv)$ Mitochondria are known as the powerhouses of the cell because they produce energy in the form of $ATP$ through cellular respiration.
$(v)$ Plastids are the sites of photosynthesis in plants and store pigments like chlorophyll.
$(vi)$ Vacuoles provide storage for nutrients and water. In some organisms,they help in the digestion of food and the expulsion of excess water and waste.

(N/A) Proteins will not be synthesized because ribosomes are the sites of protein synthesis.
$(b)$ Packaging and dispatching of materials,synthesis of complex sugars,and formation of lysosomes will be adversely affected.
$(c)$ The cell will lose its integrity,and the internal cellular contents will leak out,leading to the death of the cell.

(N/A) Role: Lysosomes act as the waste disposal system of the cell. They help in the digestion of foreign materials entering the cell,such as bacteria or food,and also remove worn-out cell organelles by digesting them.
Suicidal Bags: They are termed as 'suicidal bags' because when the cell gets damaged or its metabolic activity is disturbed,lysosomes may burst,and the digestive enzymes contained within them digest their own cell.
Mechanism: Lysosomes contain powerful digestive enzymes (hydrolytic enzymes) synthesized by the Rough Endoplasmic Reticulum $(RER)$. These enzymes are capable of breaking down all types of organic material,allowing the lysosome to digest unwanted cellular debris or foreign particles.

(N/A) The organelle is the $Vacuole$. Two substances present in it are $Amino \ acids$ and $Sugars$ (or $Proteins$, $Organic \ acids$).
$(b)$ $(i)$ In $Amoeba$, food vacuoles contain the food items captured by the organism.
$(ii)$ In many other unicellular organisms, specialized vacuoles (like contractile vacuoles) play an important role in expelling excess water and some wastes from the cell.

(N/A) $(i)$ Similarities:
$(a)$ Both are double-membrane-bound organelles.
$(b)$ Both possess their own circular $DNA$ and ribosomes (semi-autonomous nature).
$(ii)$ Dissimilarity:
Mitochondria are the sites of cellular respiration and energy production $(ATP)$,whereas plastids (specifically chloroplasts) are the sites of photosynthesis and food production.

(N/A) $(i)$

Rough endoplasmic reticulum $(RER)$	Smooth endoplasmic reticulum $(SER)$
$1.$ It appears rough under a microscope.	$1.$ It appears smooth under a microscope.
$2.$ It has ribosomes attached to its surface.	$2.$ It does not have ribosomes attached to its surface.
$3.$ It is involved in protein synthesis and transport.	$3.$ It is involved in lipid synthesis and detoxification of drugs and poisons.

$(ii)$ The proteins and lipids synthesized by the endoplasmic reticulum are essential for building the cell membrane, a process known as membrane biogenesis.

(N/A) $(i)$ Vacuoles are storage sacs for solid or liquid contents.
$(ii)$ In plant cells,vacuoles are full of cell sap and provide turgidity and rigidity to the cell.
$(iii)$ Many substances important for the life of the plant cell,such as amino acids,sugars,various organic acids,and some proteins,are stored in vacuoles.
$(b)$ If the Golgi apparatus were removed from the cell,the following would occur:
$(i)$ Packaging and dispatching of proteins to various targets inside and outside the cell would be disrupted.
$(ii)$ Cellular products could not be stored or modified.
$(iii)$ The formation of complex sugars from simple sugars would not take place.
$(iv)$ Lysosome formation would be affected,leading to the accumulation of worn-out organelles,which could result in cell death.
$(c)$ The deeply folded inner membrane of mitochondria,known as cristae,creates a large surface area for $ATP$-generating chemical reactions.

(B) Prokaryotic cells lack membrane-bound organelles such as mitochondria,lysosomes,and the endoplasmic reticulum. The only cell organelle present in prokaryotic cells is the ribosome,which is non-membrane-bound and responsible for protein synthesis.

(A) The Golgi apparatus consists of a system of membrane-bound vesicles arranged approximately parallel to each other in stacks called cisterns. These cisterns are flattened,sac-like structures that play a crucial role in the packaging and modification of proteins and lipids.

(N/A) $(i)$ The Golgi apparatus is involved in the storage of proteins and enzymes.
$(ii)$ It plays a crucial role in the modification,sorting,and packaging of materials synthesized in the cell.
$(iii)$ It is involved in the synthesis of complex sugars from simple sugars.
$(iv)$ It is responsible for the formation of lysosomes and peroxisomes.

(C) $(i)$ Defence: Lysosomes contain powerful hydrolytic enzymes that help in destroying foreign particles like bacteria and viruses that enter the cell.
$(ii)$ Digestion: They help in the intracellular digestion of food particles by breaking down complex organic molecules into simpler substances.
$(iii)$ Cleansing: They act as a waste disposal system by digesting dead,worn-out cell organelles and damaged cell components,thereby keeping the cell clean.

(N/A) The cell sap provides turgidity and rigidity to the cell,which helps in maintaining the cell's shape.
$(b)$ The $SER$ (Smooth Endoplasmic Reticulum) in liver cells plays a crucial role in detoxifying many poisons and drugs.
$(c)$ The ribosomes present on the $RER$ (Rough Endoplasmic Reticulum) are the sites of protein synthesis.

(N/A) The cell contains nuclear material which appears as an entangled mass of thread-like structures called chromatin when the cell is not dividing. During cell division,this chromatin material condenses and organizes into distinct rod-like structures known as chromosomes.
$(b)$ Chloroplasts are specialized green-colored plastids found in plant cells. They contain a green pigment called chlorophyll,which is essential for capturing light energy during photosynthesis.
$(c)$ Genes are the functional segments of $DNA$ molecules. They are located on the $DNA$ strands and act as the hereditary units that control specific traits by coding for the synthesis of specific proteins.

(N/A) Cellulose provides structural strength and helps in maintaining the shape and integrity of the cell.
$(b)$ The deeply folded membranes,known as cristae,increase the surface area for $ATP$ generating chemical reactions,thereby enhancing the efficiency of cellular respiration.
$(c)$ Digestive enzymes in lysosomes help in breaking down complex organic food into simple nutrients,digesting foreign particles like bacteria or viruses,and removing old or worn-out cell organelles through autophagy.

(N/A) The cell organelle present in both prokaryotes and eukaryotes is the $Ribosome$.

$Name \text{ of the organelle}$	$Shape \text{ and } Location$
$Ribosomes$	$Ribosomes$ are small, globular, and granular structures. In eukaryotic cells, they are either attached to the rough endoplasmic reticulum or found freely distributed in the cytoplasm. In prokaryotic cells, they are found freely in the cytoplasm.

(N/A) Plastids are double-membrane-bound organelles present only in plant cells. Like mitochondria, they contain their own $DNA$ and ribosomes, allowing them to synthesize some of their own proteins.

Type of Plastid	Function
$1$. Chloroplast	Contains chlorophyll; involved in photosynthesis to produce food.
$2$. Chromoplast	Contains pigments other than green; imparts attractive colours to flowers and fruits.
$3$. Leucoplast	Colourless plastids; primarily store starch, oils, and protein granules.

(B) The $Golgi$ $apparatus$ is primarily responsible for the packaging,modification,and secretion of proteins and lipids synthesized by the endoplasmic reticulum.
It acts as the 'post office' of the cell,where materials are sorted,packaged into vesicles,and then secreted out of the cell or transported to other organelles.

(C) The $Golgi$ $Apparatus$ is responsible for the synthesis of complex sugars from simple sugars within the cell.
It also plays a key role in the packaging and modification of proteins and lipids.

(D) According to the endosymbiotic theory,certain cell organelles are believed to have originated from independent prokaryotic organisms that were engulfed by a host cell.
These organelles,specifically $Mitochondria$ and $Plastids$ (such as chloroplasts),possess their own circular $DNA$ and $70S$ ribosomes.
Because they contain their own genetic material and protein-synthesizing machinery,they are capable of self-replication and producing some of their own proteins.
Therefore,the correct option is $D$.

(D) Ribosomes are the sites of protein synthesis in the cell.
$(i)$ Ribosomes synthesize proteins,which is their primary function.
$(ii)$ Enzymes are proteins; therefore,ribosomes are involved in their synthesis.
$(iii)$ Many hormones (peptide hormones) are proteins; therefore,ribosomes are involved in their synthesis.
$(iv)$ Starch is a polysaccharide (carbohydrate),not a protein. Ribosomes do not synthesize starch molecules; starch synthesis occurs in plastids (amyloplasts).
Thus,$(iii)$ and $(iv)$ are not functions of ribosomes in the context of direct synthesis,but specifically,$(iv)$ is definitely not a function. However,since peptide hormones are proteins,$(iii)$ is a function. The question asks for what is $NOT$ a function. Starch synthesis $(iv)$ is definitely not a function. Among the options provided,$(iii)$ and $(iv)$ are often grouped in such questions as non-ribosomal functions,though $(iii)$ is technically a protein. Given the standard curriculum,$(iv)$ is the primary non-function.

(B, C) In cell biology,organelles are classified based on their membrane structure:
$1$. Mitochondria and Plastids are double-membrane bound organelles.
$2$. Vacuoles are bound by a single membrane known as the tonoplast.
$3$. Lysosomes are also bound by a single membrane.
Since both $B$ and $C$ are single-membrane bound,in the context of standard multiple-choice questions where only one answer is expected,both are technically correct. However,if this is a single-choice question,usually $B$ or $C$ would be selected. Given the options,both Vacuole and Lysosome are single-membrane organelles.

(D) The correct answer is $D$.
$A$ is true: Mitochondria are known as the powerhouse of the cell because they produce energy in the form of $ATP$ through cellular respiration.
$B$ is true: Mitochondria and plastids are semi-autonomous organelles containing their own $DNA$ and ribosomes,allowing them to synthesize some of their own proteins. The nucleus also contains $DNA$.
$C$ is true: The Golgi apparatus plays a crucial role in packaging and modifying proteins,and it is involved in the formation of lysosomes.
$D$ is false: Protoplasm is the living content of the cell,which includes both the cytoplasm and the nucleus. Cytoplasm is only the jelly-like substance present between the cell membrane and the nucleus.

(D) $Leucoplasts$ are a type of plastid that are primarily responsible for the storage of nutrients.
They are colorless plastids that store materials such as starch, oils, and protein granules.
$Golgi$ apparatus is involved in packaging and secretion.
$Chloroplasts$ are involved in photosynthesis.
$Chromoplasts$ provide color to flowers and fruits.

(B) The Endoplasmic Reticulum $(ER)$ is a network of membrane-bound tubules and sacs.
Its structure is composed of a lipid bilayer with embedded proteins,which is fundamentally similar to the structure of the plasma membrane.
This similarity is due to the process of membrane biogenesis,where proteins and lipids synthesized by the $ER$ are used to build the plasma membrane and other cell organelles.

(C) Chloroplasts are specialized organelles found in plant cells that perform photosynthesis.
They contain the green pigment chlorophyll,which is essential for trapping light energy.
In addition to chlorophyll,chloroplasts also contain accessory pigments,specifically carotenoids,which include carotenes and xanthophylls.
Carotenes are typically orange in color,while xanthophylls are yellow.
Therefore,besides chlorophyll,chloroplasts contain yellow or orange pigments.