94 Objective Questions on Cell Biology – Viruses, Prokaryotic & Eukaryotic Cells
Dive into the fundamental world of life with this comprehensive set of 94 objective questions covering the core principles of Cell Biology, including the intricate structures of Viruses, the simple elegance of Prokaryotic Cells, and the complex organization of Eukaryotic Cells. This quiz is meticulously designed to test and reinforce your knowledge of cellular organelles like the mitochondria, ER, Golgi complex, and ribosomes, as well as crucial molecular processes such as DNA replication, transcription, and gene expression. Whether you are a student preparing for an exam or a researcher revisiting the basics, this challenge provides a rigorous assessment of your understanding of the foundational units and mechanisms that define all biological life. Let's explore the microscopic universe that constitutes life itself!
📝 The Ultimate Cell Biology Objective Questions Quiz (Verified Answers)
1. Golgi complex is not associated with :
- A. Formation of lysosomes
- B. Formation of ATPase enzymes
- C. Formation of acrosomes
- D. None of the above
2. Lysosomes contain :
- A. Protein
- B. Lipids
- C. Hydrolytic enzymes
- D. Secretory proteins
3. The enzyme ATP synthetase is present in the :
- A. Outer mitochondria membrane
- B. Mitochondrial matrix
- C. Outer compartment of mitochondria
- D. Elementary Particles (F0F1) of mitochondria
4. Proteins extending through the plasma membrane serving as carriers are referred to as :
- A. Liposome compound
- B. Intermediate
- C. Hormones
- D. Permease
5. ER is lacking in :
- A. Bacteria
- B. Ova
- C. Embryonic cells
- D. All of the above
6. Active transport is :
- A. Movement of molecules against concentration gradient
- B. Movement of molecules along contentration gradient
- C. Both (a) & (b)
- D. None of the above
7. Polysome is a chain of :
- A. Pinosomes
- B. Ribosomes
- C. Phagosomes
- D. Lysosomes
8. The gene present in mitochondria are inherited from :
- A. Both male and female parents
- B. Either male or female parents
- C. Only male parent
- D. Only female parent
9. Mitochondria are not found in :
- A. Human red blood cell
- B. Human liver cell
- C. Human nerve cell
- D. Frog liver cell
10. Cytoplasm and nucleus are separated by a membrane which is :
- A. Single layered
- B. Two-layered
- C. Three layered
- D. Multi layered
📌 Molecular Basis of Heredity and Gene Expression
11. The plasma membrane of an animal cell is composed of :
- A. Glycoproteins
- B. Phospholipoprotein
- C. Phosphoproteins
- D. None of these
12. Ribosomes can be observed in a cell by :
- A. Light microscopes
- B. Electron microscopes
- C. Both of these
- D. None of these
13. Dictyosome is also known as :
- A. Golgi body
- B. Mitochondria
- C. Ribosome
- D. Lysosome
14. Which of the following does not occur during DNA replication?
- A. Unwinding of the parent double helix
- B. Polymerisation in the directions from 3' to 5'
- C. Complementary base pairing
- D. Formation of short pieces that are united by DNA Ligase
15. Transcription :
- A. Produces only messenger RNA
- B. Requires Ribosomes
- C. Requires transfer RNA molecules
- D. Produces RNA growing from the 5' to the 3' end
16. The clover leaf model of transfer RNA was proposed by :
- A. Watson and Crick
- B. Jacob and monod
- C. Robert Holley
- D. Alexander Rich
17. Which statement is not correct?
- A. DNA codes for mRNA, tRNA and rRNA
- B. Messenger RNAs are produced on ribosomes
- C. RNAs are produced in transcription
- D. Ribosomal RNA functions in translation
18. The genes are considered as :
- A. Unit of inheritance
- B. Unit of recombination
- C. Unit of mutation
- D. All above three
19. Trisomy is expressed as :
- A. 2n+1
- B. 2n−1
- C. 2n+2
- D. 2n−2
20. DNA strands are antiparallel because of :
- A. Hydrogen bonds
- B. Phosphodiester bonds
- C. Disulphide bonds
- D. Glycosidic bonds
🧭 Cell Organelles: Structure and Function
21. DNA replication occurs in :
- A. G1 phase
- B. G2 phase
- C. S phase
- D. Inter phase
22. The enzyme that joins DNA fragments is :
- A. Restriction endonuclease
- B. Ligase
- C. Lipase
- D. Peroxidase
23. Which RNA is having least age?
- A. mRNA
- B. tRNA
- C. rRNA
- D. None of above
24. Which of the following is a function of plasma membrane?
- A. Structural barrier and cell communication
- B. Metabolic activities and cell adhesion
- C. Mass flow regulation active transport
- D. All Diffusion, endocytosis and exocytosis
25. Which of the following is not the function of ER?
- A. Electron transport
- B. Fatty acid desaturation
- C. Glycosylation of proteins during translation
- D. Glycogen breakdown
26. All of the following processes occur in the mitochondria of mammalian cells except:
- A. Fatty acid biosynthesis
- B. Protein synthesis
- C. DNA synthesis
- D. Beta oxidation of fatty acids
27. The term mitochondria was coined by -
- A. Benda
- B. Kolliker
- C. Altmann
- D. Flemming
28. Synaptonemal complex is related to -
- A. Linkage
- B. Crossing over
- C. Mutation
- D. Variation
29. Suicidal bag of the cell is -
- A. Chromosome
- B. Lysosome
- C. Ribosome
- D. Chromosome
30. A prokaryotic ribosome is -
- A. 70S
- B. 80S
- C. 60S
- D. 100S
🧬 Genetics and Chromosomal Organization
31. A chromosome with equal arms is -
- A. Metacentric
- B. Telocentric
- C. Acrocentric
- D. Acentric
32. Autolysis is related with -
- A. Golgi body
- B. Ribosome
- C. ER
- D. Lysosome
33. Which is involved in protein synthesis -
- A. Ribosome
- B. mRNA
- C. tRNA
- D. All of these
34. A polysome is a group of -
- A. Ribosomes
- B. Ribosome + Lysosome
- C. Lysosome + Chromosome
- D. All of these
35. A vector host is -
- A. Pathogenic protozoa
- B. A parasite
- C. Reservoir host
- D. Disease transmitting host
36. Molecule involved in transferring information from nucleus to cytoplasm is-
- A. DNA
- B. mRNA
- C. tRNA
- D. Protein
37. An enzyme that breaks DNA is -
- A. Endonuclease
- B. Ligase
- C. Polymerase
- D. All of the above
38. Ergastoplam is another name of -
- A. Cytoplasm
- B. Ribosome
- C. ER
- D. Lysosome
39. RNA polymerase binds to a site mRNA called -
- A. Promoter
- B. Regulator
- C. Receptor
- D. All of these
40. Polytene chromosomes were first observed by
- A. Baranetsky in 1880
- B. Heitz and Bauer in 1930
- C. Balbiani in 1881
- D. Stevens and Wilson in 1905
💊 Cell Division and Reproductive Biology
41. Crossing over begins in
- A. Pachytene
- B. Zygotene
- C. Diplotene
- D. Diakinesis
42. The acrosome of sperm is derived from
- A. Golgi complex
- B. Mitochondria
- C. Nucleus
- D. Ribosomes
43. Synthesis of RNA is inhibited during
- A. Growth phase
- B. Cleavage
- C. Fertilization
- D. Oogenesis
44. The components of the respiratory chain complex are located in
- A. Outer mitochondria membrane
- B. Inner mitochondrial membrane
- C. Golgi complex
- D. Ribosomes
45. Selective permeability is the characteristics feature of
- A. Cellwall
- B. Chromosomes
- C. Nucleolus
- D. Cell membrane
46. Nucleolus is responsible for the synthesis of
- A. Ribosomal RNA
- B. Ribosomal protein
- C. tRNA
- D. DNA
47. Fertilizin are secreted by
- A. Spermatozoa
- B. Unfertilized egg
- C. Zygote
- D. Polar bodies
48. Genetic information is routed as follows
- A. mRNA → DNA → Protein
- B. DNA → Protein → mRNA
- C. DNA → tRNA → Protein
- D. DNA → mRNA → Protein
49. "Gametes are never hybrid". This is a statement of
- A. Law of dominance
- B. Law of independent assortment
- C. Law of segregation
- D. Law of random fertilization
50. Which one is needed during DNA replication?
- A. RNA polymerase and translocase
- B. DNA polymerase and DNA ligase
- C. DNA polymerase only
- D. DNA ligase only
🧨 Aneuploidy and DNA Structural Dynamics
51. The change of chromosomal parts between non-homologous pairs of chromosomes is known as
- A. inversion
- B. translocation
- C. Deletion
- D. Duplication
52. Down's syndrome is an example of
- A. Monosomy
- B. Trisomy
- C. Triploidy
- D. Polyploidy
53. If the sequence of bases in DNA is ATTCGATG then the sequence of bases in its transcript will be
- A. CAUGGAAU
- B. UAAGCUAC
- C. GUAGCUUA
- D. AUUCGAUG
54. Kappa particles of paramecium are
- A. mRNA t protein
- B. Unmasked mRNA
- C. Cluster of ribosomes
- D. Bacteria
55. Cell division is intiated by :
- A. Centromere
- B. Chromomere
- C. Centriole
- D. Centrosome
56. Puffs (Balbiani rings) are active site of :
- A. RNA and Protein synthesis
- B. DNA synthesis
- C. Lipid synthesis
- D. Carbohydrate synthesis
57. A protoplast is :
- A. Cell organelle
- B. A cell with a wall
- C. A single wall-less cell
- D. A cell without nucleus
58. If WBCs placed in hypertonic solution, they will :
- A. Shrink and collapse
- B. Stick together
- C. Increase in volume and burst
- D. Remain normal
59. If the haploid number of chromosomes in an animal is 12, then the number of chromosomes in monosomic condition will be :
- A. 22
- B. 23
- C. 24
- D. 25
60. Wild types are generally :
- A. Recessive
- B. Dominant
- C. Co-dominant
- D. Incomplete dominant
🔥 Cellular Origins and Membrane Biology
61. Variability may originate during meiosis due to :
- A. Crossing over
- B. Chromosomal aberration
- C. Polyploidy
- D. Mutation
62. The scientist who first synthesised DNA in vitro :
- A. A. Korenberg
- B. A. Garrod
- C. J. D. Watson
- D. H.G. Khorana
63. The term mitochondria was coined by :
- A. Benda
- B. Koliker
- C. Altmann
- D. Flemming
64. A unit membrane is absent in :
- A. Ribosome
- B. Lysosome
- C. Microbody
- D. Golgi apparatus
65. Which organelle is absent in animal cell?
- A. Lysosome
- B. Golgi
- C. Endoplasmic reticulum
- D. Plastid
66. Endoplasmic reticulum is of :
- A. One type
- B. Two type
- C. Many type
- D. None of the above
67. Exchange of common segment between maternal and paternal chromatids during meiosis is called :
- A. Linkage
- B. Crossing over
- C. Dominance
- D. Mutation
68. Replication of DNA at a specific point is called :
- A. Triplicate
- B. Origin point
- C. Initiation point
- D. None of these
69. Which of the following is found only in RNA and not in DNA?
- A. Adenine
- B. Uracil
- C. Cytosine
- D. Guanine
70. Ribose and deoxyribose differ in structure around a single carbon, namely
- A. C1
- B. C2
- C. C3
- D. C4
🧪 Carbohydrates and Biomacromolecules
71. One of the following is not an aldose
- A. Glucose
- B. Galactose
- C. Mannose
- D. Fructose
72. The glycosaminoglycan that serves as an anticoagulant
- A. Heparin
- B. Hyaluronic acid
- C. Chondroitin sulfate
- D. Dermatan sulfate
73. The following polysaccharide is composed of $\beta$-glycosidic bonds
- A. Starch
- B. Glycogen
- C. Dextrin
- D. Cellulose
74. The carbon atoms involved in the osazone formation
- A. 1 and 2
- B. 2 and 3
- C. 3 and 4
- D. 5 and 6
75. Reduction division of meiosis is :
- A. Division I
- B. Division II
- C. Both
- D. None
76. The two main components of a ribosome are
- A. RNA and Proteins
- B. DNA and Proteins
- C. DNA and RNA
- D. RNA and lipids
77. Carrier molecules facilitating transport across cell membrane are
- A. Proteinaceous
- B. Fatty acids
- C. Starch
- D. Alkaloids
78. Middle lamella is a constituent of
- A. Cell membrane
- B. Cell wall
- C. Cytoplasm
- D. Nucleoplasm
79. Nucleolus takes part in synthesis of
- A. rRNA
- B. tRNA
- C. mRNA
- D. DNA
80. Glycolate metabolism occurs in
- A. Lysosome
- B. Ribosomes
- C. Glyoxysomes
- D. Peroxisomes
⛑ Cellular Metabolism and Evolution
81. Solar energy is trapped by
- A. Oxysomes
- B. Lamellae
- C. Stroma
- D. DNA
82. Lysosomes contain
- A. Carbohydrates
- B. Hormones
- C. Nucleic acids
- D. Hydrolases
83. No cell can live without
- A. Chloroplasts
- B. Proteins
- C. Enzymes
- D. Phytochrome
84. Cell theory was proposed by
- A. Schwann and Schleiden
- B. Sutton and Boveri
- C. Weismann
- D. Leeuwenhook
85. The most abundant substance in middle lamella is
- A. Cutin
- B. Lignin
- C. Pectin
- D. Suberin
86. The organelle associated with aerobic respiration is
- A. Nucleus
- B. Ribosome
- C. Chloroplast
- D. Mitochondrion
87. Which of the following stages of mitosis is the longest
- A. Prophase
- B. Metaphase
- C. Anaphase
- D. Telophase
88. Bivalents are formed during
- A. Diplotene
- B. Leptotene
- C. Zygotene
- D. Pachytene
89. Which of the following is not found in DNA
- A. U
- B. A
- C. T
- D. G
90. Which type of mutation is more frequent
- A. Transition
- B. Transversion
- C. Inversion
- D. Frameshift mutation
👁 Viruses and Microscopic Detail
91. A nucleoside differs from nucleotide in not having :
- A. Phosphate
- B. Nitrogen base
- C. Sugar
- D. Phosphate and Sugar
92. The genetic material of prokaryotic cells is called :
- A. Nucleus
- B. Nucleolus
- C. Nucleoid
- D. Chromosome
93. Which one of the following branches of biological science deals with the study of a cell and its inclusions ?
- A. Genetics
- B. Pharmacognosy
- C. Cytology
- D. Physiology
94. The occurrence of which one of the following cell organelles has been revealed by using an electron microscope?
- A. Chloroplasts
- B. Chromosomes
- C. Leucoplasts
- D. Ribosomes
This extensive quiz covering cell biology objective questions, from the nuances of prokaryotic cells quiz topics to the complexity of eukaryotic cells MCQ and even the structure of a virus MCQ, serves as a crucial study aid. Mastering these concepts is fundamental to success in biological sciences, particularly in microbiology objective questions. The interactive format allows for immediate feedback, transforming passive reading into active learning. By tackling this range of topics, students can ensure a solid grasp of cellular functions, molecular genetics, and the fundamental differences between the three domains of life and non-living viral entities. Continuous self-assessment like this is the key to achieving proficiency in this vital domain.
📚 Decoding the Cell: An In-Depth Look at Viruses, Prokaryotes, and Eukaryotes
Cell biology forms the bedrock of all biological sciences, providing the framework for understanding complex processes at the organismal level. The difference in organization between viruses, prokaryotic cells, and eukaryotic cells represents a profound evolutionary divergence, each with unique structures and molecular mechanisms for survival and propagation. A deep understanding of these distinctions, as tested in the quiz above, is essential for anyone pursuing biology, medicine, or biotechnology.
Viruses: The Obligate Intracellular Parasites
Viruses are fascinating entities that straddle the line between living and non-living. They are not true cells but are infectious agents composed of genetic material (DNA or RNA) encased in a protein coat called a capsid, and sometimes an outer lipid envelope. The core characteristic of viruses is their absolute dependency on a host cell for reproduction, classifying them as obligate intracellular parasites.
- Genetic Material: Can be single-stranded or double-stranded, DNA or RNA. This variability makes viral classification complex.
- Replication: The viral life cycle involves attachment, penetration, uncoating, replication, assembly, and release. Replication strategies vary widely based on the genome type (e.g., retroviruses use reverse transcriptase).
- Infectivity: They exhibit highly specific tropism, often infecting only a particular type of cell or organism (e.g., bacteriophages infect bacteria).
Prokaryotic Cells: Simplicity and Adaptability
Prokaryotes (Bacteria and Archaea) represent the simplest and most abundant form of life. They are typically unicellular organisms characterized by the lack of a membrane-bound nucleus and other internal organelles. Their structure is streamlined, optimizing them for rapid growth and adaptability.
The genetic material, usually a single circular chromosome, is located in an area of the cytoplasm called the nucleoid. They possess 70S ribosomes, which are smaller than the 80S ribosomes found in eukaryotes, a difference often exploited by antibiotics.
🔗 Essential Components of a Prokaryotic Cell
- Cell Wall: Provides structural support and protection, mainly composed of peptidoglycan in bacteria, distinguishing Gram-positive from Gram-negative species.
- Plasma Membrane: Controls the passage of substances and is often the site of essential metabolic activities like cellular respiration, as they lack mitochondria.
- Pili and Flagella: External structures for adhesion (pili) and motility (flagella).
The simplicity of the prokaryotic design—no nucleus, few internal membranes, and a small, circular genome—allows for incredibly rapid replication, which is key to their ecological success and evolutionary speed.
Eukaryotic Cells: Complexity and Compartmentalization
Eukaryotes (animals, plants, fungi, and protists) are defined by their extensive internal compartmentalization. The presence of a true membrane-bound nucleus and a host of specialized organelles allows for spatial separation of metabolic pathways, greatly increasing efficiency and regulation.
🌐 The Endomembrane System and Protein Trafficking
The endomembrane system includes the nuclear envelope, Endoplasmic Reticulum (ER), Golgi complex, lysosomes, and vacuoles. This system is crucial for synthesizing, modifying, packaging, and transporting proteins and lipids.
- Endoplasmic Reticulum (ER): The 'factory' of the cell. Rough ER (RER), studded with 80S ribosomes, synthesizes and modifies secreted and membrane proteins. Smooth ER (SER) is involved in lipid synthesis, detoxification, and calcium ion storage.
- Golgi Complex (Dictyosome): The 'post office' of the cell. It modifies, sorts, and packages molecules from the ER into vesicles for secretion or delivery to other organelles, such as the formation of lysosomes (the cell's "suicide bags" containing hydrolytic enzymes).
Mitochondria and Chloroplasts stand out due to their double membranes, their own circular DNA, and 70S ribosomes, strongly supporting the Endosymbiotic Theory, which posits their origin as ancient prokaryotes engulfed by an ancestral host cell. [Image of a mitochondrion structure]
✅ Frequently Asked Questions (FAQ) on Cell Biology
Q1: What is the primary difference between Transcription and Translation?
A: Transcription is the process where a segment of DNA is copied into RNA (mRNA, tRNA, or rRNA). It occurs in the nucleus of eukaryotes and the cytoplasm of prokaryotes. Translation is the process where the genetic code carried by mRNA is decoded by tRNA at the ribosome to synthesize a specific protein. It is the second step in the Central Dogma of Molecular Biology ($DNA \rightarrow RNA \rightarrow Protein$).
Q2: Why are lysosomes considered the 'suicidal bags' of the cell?
A: Lysosomes contain powerful hydrolytic enzymes capable of digesting cellular components, worn-out organelles (autophagy), or engulfed foreign material (phagocytosis). If the lysosomal membrane ruptures, these enzymes are released into the cytoplasm, leading to the self-digestion of the cell, a process known as autolysis, hence the 'suicidal bag' moniker.
Q3: How does the plasma membrane maintain selective permeability?
A: The plasma membrane's structure, primarily the phospholipid bilayer with embedded proteins, is responsible for selective permeability. Small, nonpolar molecules (like $\text{O}_2$, $\text{CO}_2$) pass easily via simple diffusion. Large or charged molecules require specific mechanisms, such as carrier proteins (permeases) for facilitated diffusion or active transport against the concentration gradient, ensuring the cell only imports necessary materials.
Q4: What is the significance of the 70S versus 80S ribosome difference?
A: 70S ribosomes are found in prokaryotes (bacteria and archaea) and the mitochondria/chloroplasts of eukaryotes. 80S ribosomes are found in the cytoplasm and Rough ER of eukaryotes. This structural difference is critical because many antibiotics are designed to target and inhibit the 70S prokaryotic ribosome without affecting the host's 80S ribosome, thereby treating bacterial infections while minimizing host cell toxicity.
👍 Key Takeaways for Cell Biology Mastery
- Membrane Fluidity: Cell membranes are dynamic structures described by the Fluid Mosaic Model, essential for transport and communication.
- Energy Centers: Mitochondria (respiration) and Chloroplasts (photosynthesis) possess their own DNA and are central to cellular energy dynamics.
- Central Dogma: The flow of genetic information is fundamentally DNA → RNA → Protein across all cellular life forms.
- Compartmentalization: Eukaryotic organelles like the ER and Golgi enable sophisticated protein and lipid processing through spatial separation.
- Prokaryotic vs. Eukaryotic: The absence or presence of a nucleus and membrane-bound organelles is the defining evolutionary split.
- Viral Parasitism: Viruses are non-cellular entities that exploit host cell machinery for all life functions, highlighting their unique place in biology.
🏁 Conclusion
The study of cell biology, encompassing the diversity from simple viruses and prokaryotes to complex eukaryotic cells, is an unending journey of discovery. The 94 objective questions presented here provide a rigorous test of fundamental knowledge, ensuring a well-rounded grasp of cellular organization, molecular genetics, and basic biochemistry. Continuous practice with questions covering cell biology objective questions, prokaryotic cells quiz, and eukaryotic cells MCQ topics is invaluable for reinforcing these core concepts. A solid foundation in cell biology is not just academic; it is the lens through which we understand health, disease, and the very nature of life itself.
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