.png)
.png)
CELL: STRUCTURE AND FUNCTIONS MCQ Test with Answers
Time Left: 45:00
Total Marks: 200, Obtained Marks: 0
1. Who first saw and described a live cell?
A. Robert Brown
B. Anton Von Leeuwenhoek
C. Matthias Schleiden
D. Theodore Schwann
Explanation:
Anton Von Leeuwenhoek was the first to observe and describe live cells, contributing significantly to cell biology.
Therefore, the correct answer is: B. Anton Von Leeuwenhoek
Anton Von Leeuwenhoek was the first to observe and describe live cells, contributing significantly to cell biology.
Therefore, the correct answer is: B. Anton Von Leeuwenhoek
2. What is the primary function of the plasma membrane?
A. Energy production
B. Selective permeability
C. Protein synthesis
D. Photosynthesis
Explanation:
The plasma membrane controls the movement of substances in and out of the cell, maintaining selective permeability.
Therefore, the correct answer is: B. Selective permeability
The plasma membrane controls the movement of substances in and out of the cell, maintaining selective permeability.
Therefore, the correct answer is: B. Selective permeability
3. What does the term "prokaryotic" signify about a cell?
A. Presence of nucleus
B. Presence of chloroplasts
C. Possession of multiple chromosomes
D. Absence of a nuclear membrane
Explanation:
Prokaryotic cells lack a nuclear membrane and membrane-bound organelles, distinguishing them from eukaryotic cells.
Therefore, the correct answer is: D. Absence of a nuclear membrane
Prokaryotic cells lack a nuclear membrane and membrane-bound organelles, distinguishing them from eukaryotic cells.
Therefore, the correct answer is: D. Absence of a nuclear membrane
4. Which organelle is known as the powerhouse of the cell?
A. Mitochondria
B. Ribosomes
C. Golgi apparatus
D. Endoplasmic reticulum
Explanation:
Mitochondria generate ATP through aerobic respiration, earning them the title "powerhouse of the cell."
Therefore, the correct answer is: A. Mitochondria
Mitochondria generate ATP through aerobic respiration, earning them the title "powerhouse of the cell."
Therefore, the correct answer is: A. Mitochondria
5. What structure is responsible for protein synthesis in cells?
A. Mitochondria
B. Golgi apparatus
C. Ribosomes
D. Lysosomes
Explanation:
Ribosomes, found in both prokaryotic and eukaryotic cells, are the primary sites of protein synthesis.
Therefore, the correct answer is: C. Ribosomes
Ribosomes, found in both prokaryotic and eukaryotic cells, are the primary sites of protein synthesis.
Therefore, the correct answer is: C. Ribosomes
6. Who proposed the cell theory along with Matthias Schleiden?
A. Theodore Schwann
B. Robert Brown
C. Rudolf Virchow
D. Anton Von Leeuwenhoek
Explanation:
Theodore Schwann, a British Zoologist, collaborated with Matthias Schleiden to propose the cell theory.
Therefore, the correct answer is: A. Theodore Schwann
Theodore Schwann, a British Zoologist, collaborated with Matthias Schleiden to propose the cell theory.
Therefore, the correct answer is: A. Theodore Schwann
7. Which organelle is involved in the synthesis of lipids?
A. Golgi apparatus
B. Smooth endoplasmic reticulum
C. Ribosomes
D. Lysosomes
Explanation:
The smooth endoplasmic reticulum (SER) is responsible for lipid synthesis and metabolism.
Therefore, the correct answer is: B. Smooth endoplasmic reticulum
The smooth endoplasmic reticulum (SER) is responsible for lipid synthesis and metabolism.
Therefore, the correct answer is: B. Smooth endoplasmic reticulum
8. What structure within the chloroplast contains chlorophyll?
A. Stroma
B. Thylakoids
C. Grana
D. Lamellae
Explanation:
Chlorophyll, essential for photosynthesis, is found in the thylakoids of the chloroplast.
Therefore, the correct answer is: B. Thylakoids
Chlorophyll, essential for photosynthesis, is found in the thylakoids of the chloroplast.
Therefore, the correct answer is: B. Thylakoids
9. What is the sedimentation coefficient of prokaryotic ribosomes?
A. 80S
B. 70S
C. 90S
D. 50S
Explanation:
Prokaryotic ribosomes have a sedimentation coefficient of 70S, composed of 50S and 30S subunits.
Therefore, the correct answer is: B. 70S
Prokaryotic ribosomes have a sedimentation coefficient of 70S, composed of 50S and 30S subunits.
Therefore, the correct answer is: B. 70S
10. What is the main component of the plant cell wall?
A. Galactans
B. Proteins
C. Cellulose
D. Lipids
Explanation:
The plant cell wall is primarily composed of cellulose, providing rigidity and structural support.
Therefore, the correct answer is: C. Cellulose
The plant cell wall is primarily composed of cellulose, providing rigidity and structural support.
Therefore, the correct answer is: C. Cellulose
11. What is the role of the Golgi apparatus?
A. Packaging and modification of proteins
B. Lipid synthesis
C. Photosynthesis
D. ATP production
Explanation:
The Golgi apparatus modifies, sorts, and packages proteins and lipids for storage or transport out of the cell.
Therefore, the correct answer is: A. Packaging and modification of proteins
The Golgi apparatus modifies, sorts, and packages proteins and lipids for storage or transport out of the cell.
Therefore, the correct answer is: A. Packaging and modification of proteins
12. Which organelle is known as the site of aerobic respiration?
A. Mitochondria
B. Ribosomes
C. Golgi apparatus
D. Lysosomes
Explanation:
Mitochondria are responsible for aerobic respiration and ATP production, making them the "powerhouse" of the cell.
Therefore, the correct answer is: A. Mitochondria
Mitochondria are responsible for aerobic respiration and ATP production, making them the "powerhouse" of the cell.
Therefore, the correct answer is: A. Mitochondria
13. What is the function of lysosomes?
A. Protein synthesis
B. DNA replication
C. Lipid synthesis
D. Digestion of macromolecules
Explanation:
Lysosomes contain hydrolytic enzymes that digest proteins, lipids, and carbohydrates, aiding in waste removal.
Therefore, the correct answer is: D. Digestion of macromolecules
Lysosomes contain hydrolytic enzymes that digest proteins, lipids, and carbohydrates, aiding in waste removal.
Therefore, the correct answer is: D. Digestion of macromolecules
14. Which type of cell lacks a membrane-bound nucleus?
A. Eukaryotic
B. Prokaryotic
C. Animal cell
D. Plant cell
Explanation:
Prokaryotic cells lack a membrane-bound nucleus, differentiating them from eukaryotic cells.
Therefore, the correct answer is: B. Prokaryotic
Prokaryotic cells lack a membrane-bound nucleus, differentiating them from eukaryotic cells.
Therefore, the correct answer is: B. Prokaryotic
15. What pigment is found in chloroplasts that traps light energy?
A. Carotene
B. Chlorophyll
C. Xanthophyll
D. Hemoglobin
Explanation:
Chlorophyll is the green pigment in chloroplasts that captures light energy for photosynthesis.
Therefore, the correct answer is: B. Chlorophyll
Chlorophyll is the green pigment in chloroplasts that captures light energy for photosynthesis.
Therefore, the correct answer is: B. Chlorophyll
16. What does the term "cytoplasm" refer to in a cell?
A. The semi-fluid matrix inside the cell
B. The rigid outer boundary
C. The genetic material
D. The cell wall
Explanation:
The cytoplasm is a semi-fluid matrix in the cell where various chemical reactions occur, maintaining cellular life.
Therefore, the correct answer is: A. The semi-fluid matrix inside the cell
The cytoplasm is a semi-fluid matrix in the cell where various chemical reactions occur, maintaining cellular life.
Therefore, the correct answer is: A. The semi-fluid matrix inside the cell
17. Which structure in bacteria provides antibiotic resistance?
A. Mesosome
B. Plasmid
C. Ribosome
D. Pili
Explanation:
Plasmids are small, circular DNA in bacteria that often carry genes conferring antibiotic resistance.
Therefore, the correct answer is: B. Plasmid
Plasmids are small, circular DNA in bacteria that often carry genes conferring antibiotic resistance.
Therefore, the correct answer is: B. Plasmid
18. Which organelle contains enzymes for digestion and waste removal?
A. Lysosomes
B. Vacuoles
C. Ribosomes
D. Chloroplasts
Explanation:
Lysosomes are vesicular structures rich in hydrolytic enzymes that digest waste and cellular debris.
Therefore, the correct answer is: A. Lysosomes
Lysosomes are vesicular structures rich in hydrolytic enzymes that digest waste and cellular debris.
Therefore, the correct answer is: A. Lysosomes
19. What is the function of the nucleus in a cell?
A. ATP production
B. Control of cellular activities
C. Photosynthesis
D. Digestion of food
Explanation:
The nucleus regulates cellular activities, stores genetic material, and coordinates growth and reproduction.
Therefore, the correct answer is: B. Control of cellular activities
The nucleus regulates cellular activities, stores genetic material, and coordinates growth and reproduction.
Therefore, the correct answer is: B. Control of cellular activities
20. Which is the smallest cell observed in living organisms?
A. Bacteria
B. Mycoplasma
C. Red blood cells
D. Nerve cells
Explanation:
Mycoplasmas are the smallest known cells, with a size of about 0.3 µm in diameter.
Therefore, the correct answer is: B. Mycoplasma
Mycoplasmas are the smallest known cells, with a size of about 0.3 µm in diameter.
Therefore, the correct answer is: B. Mycoplasma
21. What is the structural and functional unit of life?
A. Tissue
B. Organ
C. Cell
D. Organ system
Explanation:
Cells are the basic structural and functional units of all living organisms.
Therefore, the correct answer is: C. Cell
Cells are the basic structural and functional units of all living organisms.
Therefore, the correct answer is: C. Cell
22. Which cell organelle is involved in detoxification of harmful substances?
A. Ribosomes
B. Smooth endoplasmic reticulum
C. Lysosomes
D. Vacuoles
Explanation:
The smooth endoplasmic reticulum (SER) plays a key role in the detoxification of harmful substances in cells.
Therefore, the correct answer is: B. Smooth endoplasmic reticulum
The smooth endoplasmic reticulum (SER) plays a key role in the detoxification of harmful substances in cells.
Therefore, the correct answer is: B. Smooth endoplasmic reticulum
23. Which structure in prokaryotic cells aids in respiration and DNA replication?
A. Plasmid
B. Mesosome
C. Flagella
D. Ribosomes
Explanation:
Mesosomes, which are extensions of the plasma membrane in prokaryotes, help in respiration and DNA replication.
Therefore, the correct answer is: B. Mesosome
Mesosomes, which are extensions of the plasma membrane in prokaryotes, help in respiration and DNA replication.
Therefore, the correct answer is: B. Mesosome
24. What type of ribosomes are found in eukaryotic cells?
A. 50S
B. 70S
C. 80S
D. 90S
Explanation:
Eukaryotic cells contain 80S ribosomes, which are larger and more complex than prokaryotic ribosomes.
Therefore, the correct answer is: C. 80S
Eukaryotic cells contain 80S ribosomes, which are larger and more complex than prokaryotic ribosomes.
Therefore, the correct answer is: C. 80S
25. What is the site of protein synthesis in cells?
A. Lysosomes
B. Golgi apparatus
C. Ribosomes
D. Vacuoles
Explanation:
Ribosomes, found in the cytoplasm and on the rough endoplasmic reticulum, are the primary site of protein synthesis.
Therefore, the correct answer is: C. Ribosomes
Ribosomes, found in the cytoplasm and on the rough endoplasmic reticulum, are the primary site of protein synthesis.
Therefore, the correct answer is: C. Ribosomes
26. Which cell organelle is known as the 'kitchen of the cell'?
A. Chloroplast
B. Mitochondria
C. Nucleus
D. Lysosomes
Explanation:
Chloroplasts are responsible for photosynthesis, producing food for the cell, earning them the nickname 'kitchen of the cell.'
Therefore, the correct answer is: A. Chloroplast
Chloroplasts are responsible for photosynthesis, producing food for the cell, earning them the nickname 'kitchen of the cell.'
Therefore, the correct answer is: A. Chloroplast
27. What structure connects the cytoplasm of neighboring plant cells?
A. Plasma membrane
B. Middle lamella
C. Plasmodesmata
D. Cell wall
Explanation:
Plasmodesmata are microscopic channels that connect the cytoplasm of adjacent plant cells, allowing communication and transport.
Therefore, the correct answer is: C. Plasmodesmata
Plasmodesmata are microscopic channels that connect the cytoplasm of adjacent plant cells, allowing communication and transport.
Therefore, the correct answer is: C. Plasmodesmata
28. What is the primary function of mitochondria?
A. Protein synthesis
B. ATP production
C. Lipid synthesis
D. Photosynthesis
Explanation:
Mitochondria are the site of aerobic respiration, producing ATP, which is the energy currency of the cell.
Therefore, the correct answer is: B. ATP production
Mitochondria are the site of aerobic respiration, producing ATP, which is the energy currency of the cell.
Therefore, the correct answer is: B. ATP production
29. Which organelle has a 9+2 arrangement of microtubules?
A. Cilia and flagella
B. Centrioles
C. Ribosomes
D. Golgi apparatus
Explanation:
The core of cilia and flagella, called the axoneme, has a characteristic 9+2 arrangement of microtubules.
Therefore, the correct answer is: A. Cilia and flagella
The core of cilia and flagella, called the axoneme, has a characteristic 9+2 arrangement of microtubules.
Therefore, the correct answer is: A. Cilia and flagella
30. What is the function of the Golgi apparatus?
A. Photosynthesis
B. Lipid synthesis
C. ATP production
D. Packaging and modification of proteins
Explanation:
The Golgi apparatus is responsible for packaging and modifying proteins for secretion or use within the cell.
Therefore, the correct answer is: D. Packaging and modification of proteins
The Golgi apparatus is responsible for packaging and modifying proteins for secretion or use within the cell.
Therefore, the correct answer is: D. Packaging and modification of proteins
31. Which organelle is involved in photosynthesis?
A. Mitochondria
B. Chloroplast
C. Ribosomes
D. Golgi apparatus
Explanation:
Chloroplasts contain chlorophyll, which traps light energy and enables the process of photosynthesis.
Therefore, the correct answer is: B. Chloroplast
Chloroplasts contain chlorophyll, which traps light energy and enables the process of photosynthesis.
Therefore, the correct answer is: B. Chloroplast
32. What are the main components of the plasma membrane?
A. DNA and proteins
B. Carbohydrates and RNA
C. Lipids and proteins
D. Cellulose and hemicellulose
Explanation:
The plasma membrane is primarily composed of a lipid bilayer with embedded proteins, as described by the fluid mosaic model.
Therefore, the correct answer is: C. Lipids and proteins
The plasma membrane is primarily composed of a lipid bilayer with embedded proteins, as described by the fluid mosaic model.
Therefore, the correct answer is: C. Lipids and proteins
33. Which organelle is known as the 'control center' of the cell?
A. Mitochondria
B. Nucleus
C. Chloroplast
D. Golgi apparatus
Explanation:
The nucleus controls cellular activities and stores the genetic material, which is essential for cell regulation and reproduction.
Therefore, the correct answer is: B. Nucleus
The nucleus controls cellular activities and stores the genetic material, which is essential for cell regulation and reproduction.
Therefore, the correct answer is: B. Nucleus
34. What is the term for the DNA found in mitochondria?
A. Linear DNA
B. Circular DNA
C. Plasmid
D. Chromosomal DNA
Explanation:
Mitochondria have their own circular DNA, which enables them to replicate and perform protein synthesis independently.
Therefore, the correct answer is: B. Circular DNA
Mitochondria have their own circular DNA, which enables them to replicate and perform protein synthesis independently.
Therefore, the correct answer is: B. Circular DNA
35. Which structure provides structural support to plant cells?
A. Cell wall
B. Plasma membrane
C. Cytoplasm
D. Chloroplast
Explanation:
The cell wall, composed of cellulose in plants, provides rigidity and structural support to plant cells.
Therefore, the correct answer is: A. Cell wall
The cell wall, composed of cellulose in plants, provides rigidity and structural support to plant cells.
Therefore, the correct answer is: A. Cell wall
36. What type of chromosomes have a terminal centromere?
A. Metacentric
B. Sub-metacentric
C. Acrocentric
D. Telocentric
Explanation:
Telocentric chromosomes have their centromere located at the terminal end, resulting in one long arm.
Therefore, the correct answer is: D. Telocentric
Telocentric chromosomes have their centromere located at the terminal end, resulting in one long arm.
Therefore, the correct answer is: D. Telocentric
37. Which part of the cell is responsible for lipid synthesis?
A. Smooth endoplasmic reticulum
B. Ribosomes
C. Lysosomes
D. Mitochondria
Explanation:
The smooth endoplasmic reticulum (SER) synthesizes lipids, including steroids and phospholipids.
Therefore, the correct answer is: A. Smooth endoplasmic reticulum
The smooth endoplasmic reticulum (SER) synthesizes lipids, including steroids and phospholipids.
Therefore, the correct answer is: A. Smooth endoplasmic reticulum
38. What is the primary function of ribosomes?
A. DNA replication
B. Protein synthesis
C. Lipid synthesis
D. ATP production
Explanation:
Ribosomes are responsible for synthesizing proteins by translating messenger RNA (mRNA).
Therefore, the correct answer is: B. Protein synthesis
Ribosomes are responsible for synthesizing proteins by translating messenger RNA (mRNA).
Therefore, the correct answer is: B. Protein synthesis
39. Which structure in bacteria helps in attachment to surfaces?
A. Pili
B. Flagella
C. Plasmids
D. Mesosomes
Explanation:
Pili are hair-like structures in bacteria that aid in attachment to surfaces and facilitate genetic material exchange.
Therefore, the correct answer is: A. Pili
Pili are hair-like structures in bacteria that aid in attachment to surfaces and facilitate genetic material exchange.
Therefore, the correct answer is: A. Pili
40. Which organelle is responsible for packaging and modifying proteins?
A. Ribosomes
B. Smooth endoplasmic reticulum
C. Golgi apparatus
D. Mitochondria
Explanation:
The Golgi apparatus processes and packages proteins into vesicles for secretion or intracellular use.
Therefore, the correct answer is: C. Golgi apparatus
The Golgi apparatus processes and packages proteins into vesicles for secretion or intracellular use.
Therefore, the correct answer is: C. Golgi apparatus
41. What is the name of the semi-fluid matrix in cells?
A. Cytoplasm
B. Nucleoplasm
C. Stroma
D. Matrix
Explanation:
The cytoplasm is a semi-fluid matrix that fills the cell, housing organelles and facilitating chemical reactions.
Therefore, the correct answer is: A. Cytoplasm
The cytoplasm is a semi-fluid matrix that fills the cell, housing organelles and facilitating chemical reactions.
Therefore, the correct answer is: A. Cytoplasm
42. What is the term for the DNA found in prokaryotes?
A. Linear DNA
B. Double-stranded RNA
C. Circular DNA
D. Plasmids
Explanation:
Prokaryotes contain circular DNA as their genetic material, which is not enclosed within a nuclear membrane.
Therefore, the correct answer is: C. Circular DNA
Prokaryotes contain circular DNA as their genetic material, which is not enclosed within a nuclear membrane.
Therefore, the correct answer is: C. Circular DNA
43. Which cell structure is composed of cellulose in plants?
A. Plasma membrane
B. Cell wall
C. Chloroplast
D. Nucleus
Explanation:
The cell wall in plants is primarily composed of cellulose, providing structural support and protection.
Therefore, the correct answer is: B. Cell wall
The cell wall in plants is primarily composed of cellulose, providing structural support and protection.
Therefore, the correct answer is: B. Cell wall
44. What is the name of the pigment responsible for the red, yellow, and orange colors in plants?
A. Chlorophyll
B. Hemoglobin
C. Carotenoids
D. Phycobilins
Explanation:
Carotenoids are pigments that provide red, orange, and yellow colors in plant parts, such as fruits and flowers.
Therefore, the correct answer is: C. Carotenoids
Carotenoids are pigments that provide red, orange, and yellow colors in plant parts, such as fruits and flowers.
Therefore, the correct answer is: C. Carotenoids
45. What is the function of centrioles in animal cells?
A. ATP production
B. Formation of spindle fibers
C. Protein synthesis
D. Photosynthesis
Explanation:
Centrioles play a key role in forming spindle fibers, which are essential for chromosome separation during cell division.
Therefore, the correct answer is: B. Formation of spindle fibers
Centrioles play a key role in forming spindle fibers, which are essential for chromosome separation during cell division.
Therefore, the correct answer is: B. Formation of spindle fibers
46. What is the term for the interconnected network of membranes within a cell?
A. Ribosomes
B. Endoplasmic reticulum
C. Golgi apparatus
D. Cytoskeleton
Explanation:
The endoplasmic reticulum (ER) is an interconnected network of membranes, involved in protein and lipid synthesis.
Therefore, the correct answer is: B. Endoplasmic reticulum
The endoplasmic reticulum (ER) is an interconnected network of membranes, involved in protein and lipid synthesis.
Therefore, the correct answer is: B. Endoplasmic reticulum
47. Which organelle helps in osmoregulation in freshwater protozoa?
A. Contractile vacuole
B. Lysosome
C. Chloroplast
D. Mitochondria
Explanation:
The contractile vacuole in protozoa helps maintain water balance by expelling excess water from the cell.
Therefore, the correct answer is: A. Contractile vacuole
The contractile vacuole in protozoa helps maintain water balance by expelling excess water from the cell.
Therefore, the correct answer is: A. Contractile vacuole
48. What pigment is present in the thylakoids of chloroplasts?
A. Carotenoids
B. Xanthophyll
C. Chlorophyll
D. Hemoglobin
Explanation:
Chlorophyll is the pigment in thylakoids responsible for capturing light energy during photosynthesis.
Therefore, the correct answer is: C. Chlorophyll
Chlorophyll is the pigment in thylakoids responsible for capturing light energy during photosynthesis.
Therefore, the correct answer is: C. Chlorophyll
49. Which process occurs in mitochondria?
A. Photosynthesis
B. Aerobic respiration
C. Protein synthesis
D. Lipid synthesis
Explanation:
Mitochondria are the site of aerobic respiration, where ATP is generated for cellular energy.
Therefore, the correct answer is: B. Aerobic respiration
Mitochondria are the site of aerobic respiration, where ATP is generated for cellular energy.
Therefore, the correct answer is: B. Aerobic respiration
50. Which organelle is involved in the synthesis of ribosomal RNA?
A. Lysosomes
B. Nucleolus
C. Ribosomes
D. Golgi apparatus
Explanation:
The nucleolus, located in the nucleus, is responsible for synthesizing ribosomal RNA and assembling ribosomal subunits.
Therefore, the correct answer is: B. Nucleolus
The nucleolus, located in the nucleus, is responsible for synthesizing ribosomal RNA and assembling ribosomal subunits.
Therefore, the correct answer is: B. Nucleolus
