Characteristics of Prokaryotic and Eukaryotic Cells, Exams of Microbiology

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BIOD171 MICROBIOLOGY

Module 1

Final Exam Review

Q & A

1. Which of the following is a unique characteristic of prokaryotic cells? A) Nucleus B) Mitochondria C) Peptidoglycan cell wall D) Endoplasmic reticulum Answer: C) Peptidoglycan cell wall Rationale: Prokaryotic cells are distinguished by having a peptidoglycan cell wall, which eukaryotic cells lack. This structure provides strength and rigidity to the cell.
2. In the context of microbiology, what is the primary function of ribosomes? A) DNA replication B) Protein synthesis C) Energy production D) Cell division Answer: B) Protein synthesis Rationale: Ribosomes are the cellular organelles responsible for protein synthesis, translating genetic information into functional proteins.
3. Which cellular organelle is responsible for the detoxification of harmful substances in eukaryotic cells? A) Golgi apparatus B) Lysosome C) Peroxisome D) Nucleolus Answer: C) Peroxisome Rationale: Peroxisomes contain enzymes that neutralize toxins, such as hydrogen peroxide, making them crucial for detoxification processes in the cell.
4. What is the primary difference between the cell walls of gram-positive and gram-negative bacteria? A) Thickness of peptidoglycan layer B) Presence of a plasma membrane C) Type of ribosomes present D) Size of the cell Answer: A) Thickness of peptidoglycan layer

Rationale: Gram-positive bacteria have a thick peptidoglycan layer, which retains the crystal violet stain used in Gram staining, while gram-negative bacteria have a thin layer and do not retain the stain.

5. Which of the following best describes the arrangement of bacterial DNA? A) Enclosed within a nuclear envelope B) Linear chromosomes C) Single circular chromosome D) Multiple circular chromosomes Answer: C) Single circular chromosome Rationale: Bacterial DNA typically exists as a single circular chromosome, which is not enclosed in a nucleus.
6. What is the function of the smooth endoplasmic reticulum in eukaryotic cells? A) Protein synthesis B) Lipid synthesis C) DNA replication D) Photosynthesis Answer: B) Lipid synthesis Rationale: The smooth endoplasmic reticulum is involved in the synthesis of lipids, including steroids and phospholipids, which are essential components of cell membranes.
7. Which of the following is not a component of the endomembrane system in eukaryotic cells? A) Mitochondria B) Golgi apparatus C) Endoplasmic reticulum D) Lysosomes Answer: A) Mitochondria Rationale: The endomembrane system includes the endoplasmic reticulum, Golgi apparatus, and lysosomes, but not the mitochondria, which is an independent organelle with its own DNA.
8. In microbiology, what is the significance of the capsule found in some bacterial cells?

A) It aids in protein synthesis. B) It is the site of cellular respiration. C) It provides protection against phagocytosis. D) It is involved in DNA replication. Answer: C) It provides protection against phagocytosis. Rationale: The capsule is a polysaccharide layer that surrounds some bacteria, providing protection against phagocytosis by host immune cells.

9. What is the role of flagella in bacterial cells? A) Energy production B) Cell division C) Movement D) Protein synthesis Answer: C) Movement Rationale: Flagella are long, whip-like structures that provide motility to bacterial cells, allowing them to move towards nutrients or away from harmful substances.
10. Which of the following best describes plasmids? A) Membrane-bound organelles B) Extrachromosomal DNA molecules C) Structures for waste removal D) Sites of viral attachment Answer: B) Extrachromosomal DNA molecules Rationale: Plasmids are small, circular DNA molecules found in bacteria that are separate from the chromosomal DNA and can carry genes beneficial for survival.
11. How do antibiotics typically target bacterial cells without harming eukaryotic cells? A) By disrupting the nuclear envelope B) By inhibiting protein synthesis in ribosomes C) By attacking the peptidoglycan cell wall D) By altering the mitochondrial DNA Answer: C) By attacking the peptidoglycan cell wall Rationale: Antibiotics often target structures unique to bacteria, such as the peptidoglycan cell wall, which is not present in eukaryotic cells, thus avoiding harm to the host cells.

12. What is the primary role of the nucleoid region in prokaryotic cells? A) It stores calcium ions. B) It is the site of lipid synthesis. C) It contains the genetic material. D) It is involved in cell division. Answer: C) It contains the genetic material. Rationale: The nucleoid region in prokaryotic cells is where the DNA is located, serving as the control center for the cell's activity and replication.
13. Which organelle is known as the 'powerhouse of the cell' due to its role in energy production? A) Chloroplast B) Nucleus C) Mitochondrion D) Ribosome Answer: C) Mitochondrion Rationale: The mitochondrion is responsible for producing ATP, the cell's energy currency, through the process of cellular respiration.
14. What is the significance of binary fission in bacterial reproduction? A) It increases genetic diversity through sexual reproduction. B) It allows for the rapid multiplication of bacterial cells. C) It results in the formation of spores. D) It involves the exchange of genetic material between cells. Answer: B) It allows for the rapid multiplication of bacterial cells. Rationale: Binary fission is a form of asexual reproduction in bacteria that leads to a rapid increase in cell numbers, which is significant for both bacterial growth and pathogenesis. Which of the following is a characteristic of prokaryotic cells? A. Presence of a nucleus B. Lack of membrane-bound organelles C. Large size D. Presence of mitochondria Answer: B. Lack of membrane-bound organelles

Rationale: Prokaryotic cells do not possess membrane-bound organelles like eukaryotic cells. Their genetic material is not enclosed within a nucleus. Which of the following is a eukaryotic organelle responsible for energy production? A. Vacuole B. Golgi apparatus C. Mitochondrion D. Ribosome Answer: C. Mitochondrion Rationale: Mitochondria are known as the powerhouses of the cell, responsible for generating ATP through cellular respiration. What is the function of the endoplasmic reticulum in eukaryotic cells? A. Protein synthesis B. Lipid synthesis C. DNA replication D. Energy production Answer: A. Protein synthesis Rationale: The endoplasmic reticulum (ER) is involved in protein synthesis and folding in eukaryotic cells. Which type of microorganism is known for its ability to survive extreme conditions? A. Virus B. Bacteria C. Fungus D. Protozoa Answer: B. Bacteria Rationale: Certain bacteria, such as extremophiles, have adaptations that allow them to thrive in extreme environments like high temperatures or

acidity. How do prokaryotic and eukaryotic cells differ in terms of genetic material? A. Prokaryotic cells have linear DNA, while eukaryotic cells have circular DNA. B. Prokaryotic cells lack DNA, while eukaryotic cells have double- stranded DNA. C. Prokaryotic cells have a single chromosome, while eukaryotic cells have multiple chromosomes. D. Prokaryotic cells have RNA as their genetic material, while eukaryotic cells have DNA. Answer: C. Prokaryotic cells have a single chromosome, while eukaryotic cells have multiple chromosomes. Rationale: Prokaryotic cells typically contain a single circular chromosome, whereas eukaryotic cells have multiple linear chromosomes.

1. Which of the following characteristics differentiate prokaryotic and eukaryotic cells? A) Prokaryotic cells have a nucleus, eukaryotic cells do not. B) Eukaryotic cells have a cell membrane, prokaryotic cells do not. C) Eukaryotic cells have membrane-bound organelles, prokaryotic cells do not. D) Prokaryotic cells have a cell wall, eukaryotic cells do not. Answer: C) Eukaryotic cells have membrane-bound organelles, prokaryotic cells do not. Rationale: Prokaryotic cells lack membrane-bound organelles, such as the nucleus, endoplasmic reticulum, and mitochondria, that are present in eukaryotic cells.
2. Which of the following is a prokaryotic organism? A) Bacteria B) Fungi C) Protists D) Plants

Answer: A) Bacteria Rationale: Bacteria are unicellular prokaryotic organisms that lack a nucleus and membrane-bound organelles.

3. Which cellular organelle is responsible for the production of ATP in eukaryotic cells? A) Nucleus B) Golgi apparatus C) Mitochondrion D) Endoplasmic reticulum Answer: C) Mitochondrion Rationale: The mitochondrion is the powerhouse of the cell and is responsible for producing ATP through cellular respiration.
4. What is the function of ribosomes in both prokaryotic and eukaryotic cells? A) Protein synthesis B) DNA replication C) ATP production D) Lipid synthesis Answer: A) Protein synthesis Rationale: Ribosomes are responsible for protein synthesis in both prokaryotic and eukaryotic cells by translating mRNA into amino acid sequences.
5. Which of the following organelles is responsible for detoxifying harmful substances in the cell? A) Lysosome B) Peroxisome C) Golgi apparatus D) Endoplasmic reticulum Answer: B) Peroxisome Rationale: Peroxisomes are responsible for detoxifying harmful substances in the cell, such as hydrogen peroxide, through the use of catalase enzymes.
6. Which of the following is a characteristic of eukaryotic cells but not prokaryotic cells?

A) Cell wall B) Flagella C) Endoplasmic reticulum D) Plasmid Answer: C) Endoplasmic reticulum Rationale: The endoplasmic reticulum is a membrane-bound organelle found in eukaryotic cells that is responsible for protein and lipid synthesis.

7. What is the main function of the nucleus in eukaryotic cells? A) Protein synthesis B) ATP production C) Genetic information storage D) Detoxification Answer: C) Genetic information storage Rationale: The nucleus contains the cell's genetic material, including DNA, and is responsible for storing and transmitting genetic information.
8. Which of the following is a characteristic of both prokaryotic and eukaryotic cells? A) Cell membrane B) Cell wall C) Nucleus D) Mitochondria Answer: A) Cell membrane Rationale: Both prokaryotic and eukaryotic cells have a cell membrane that surrounds and protects the cell.
9. What is the function of the Golgi apparatus in eukaryotic cells? A) Protein synthesis B) Lipid synthesis C) Transport and modification of proteins D) ATP production Answer: C) Transport and modification of proteins Rationale: The Golgi apparatus is responsible for packaging, modifying, and transporting proteins to their final destination within the cell or outside of the cell.
10. Which of the following is an example of a prokaryotic organism?

A) Amoeba B) Yeast C) E. coli D) Plant Answer: C) E. coli Rationale: E. coli is a bacterium that is classified as a prokaryotic organism due to its lack of a nucleus and membrane-bound organelles.

11. Which organelle is responsible for maintaining cell shape and providing structural support in plant cells? A) Chloroplast B) Vacuole C) Cell wall D) Nucleus Answer: C) Cell wall Rationale: The cell wall is a rigid structure found in plant cells that provides support and maintains cell shape.
12. What is the function of the lysosome in eukaryotic cells? A) Protein synthesis B) ATP production C) Digestion of cellular waste D) Photosynthesis Answer: C) Digestion of cellular waste Rationale: Lysosomes are membrane-bound organelles that contain enzymes responsible for breaking down cellular waste and foreign materials.
13. Which cellular organelle is responsible for photosynthesis in plant cells? A) Nucleus B) Golgi apparatus C) Mitochondrion D) Chloroplast Answer: D) Chloroplast Rationale: Chloroplasts are responsible for photosynthesis in plant cells, where they convert sunlight into energy in the form of glucose.

14. Which of the following organelles is responsible for detoxification, lipid metabolism, and calcium storage in eukaryotic cells? A) Golgi apparatus B) Peroxisome C) Endoplasmic reticulum D) Lysosome Answer: C) Endoplasmic reticulum Rationale: The endoplasmic reticulum plays a crucial role in detoxification, lipid metabolism, and calcium storage in eukaryotic cells.
15. Which of the following structures are present in both prokaryotic and eukaryotic cells? A) Flagella B) Nucleus C) Cell wall D) Mitochondria Answer: A) Flagella Rationale: Flagella are present in both prokaryotic and eukaryotic cells and are responsible for cell motility.
16. Which organelle is responsible for the synthesis and modification of proteins in eukaryotic cells? A) Lysosome B) Endoplasmic reticulum C) Golgi apparatus D) Mitochondrion Answer: B) Endoplasmic reticulum Rationale: The endoplasmic reticulum is responsible for the synthesis and modification of proteins in eukaryotic cells before they are transported to the Golgi apparatus for further processing.
17. Which of the following structures are unique to plant cells and not found in animal cells? A) Cell membrane B) Chloroplasts C) Vacuole D) Mitochondria Answer: B) Chloroplasts

Rationale: Chloroplasts are unique to plant cells and are responsible for photosynthesis, converting light energy into chemical energy.

18. What is the function of the vacuole in plant cells? A) Energy production B) Storage of water and nutrients C) Protein synthesis D) Detoxification Answer: B) Storage of water and nutrients Rationale: Vacuoles in plant cells serve as storage compartments for water, nutrients, and waste products, contributing to the plant's turgidity and structural support.
19. Which of the following cellular organelles is responsible for breaking down and recycling cellular components? A) Peroxisome B) Lysosome C) Mitochondrion D) Chloroplast Answer: B) Lysosome Rationale: Lysosomes contain enzymes that break down and recycle cellular components, such as proteins, lipids, and organelles.
20. What is the function of the flagella in prokaryotic cells? A) Protein synthesis B) Cell motility C) Energy production D) DNA replication Answer: B) Cell motility Rationale: Flagella are whip-like structures found on the surface of prokaryotic cells that enable them to move through liquid environments.
21. Which of the following is a characteristic of prokaryotic cells but not eukaryotic cells? A) Cell membrane B) Nucleus C) Cell wall D) Endoplasmic reticulum

Answer: C) Cell wall Rationale: Prokaryotic cells have a cell wall made of peptidoglycan that provides structure and protection, while eukaryotic cells lack a cell wall or have a different composition.

22. Which of the following cellular organelles is responsible for conducting cellular respiration and producing ATP in eukaryotic cells? A) Lysosome B) Mitochondrion C) Golgi apparatus D) Peroxisome Answer: B) Mitochondrion Rationale: Mitochondria are the powerhouse of the cell and are responsible for conducting cellular respiration to produce ATP for cellular energy.
23. What is the function of the nuclear membrane in eukaryotic cells? A) Regulation of gene expression B) Protection of genetic material C) Energy production D) Protein synthesis Answer: B) Protection of genetic material Rationale: The nuclear membrane surrounds and protects the cell's genetic material, including DNA, in the nucleus of eukaryotic cells.
24. Which of the following organelles is responsible for storing water, nutrients, and waste products in plant cells? A) Nucleus B) Chloroplast C) Vacuole D) Cell wall Answer: C) Vacuole Rationale: Vacuoles in plant cells play a crucial role in storing water, nutrients, and waste products, contributing to the plant's growth and development.
25. What is the function of the cell membrane in both prokaryotic and eukaryotic cells?

A) Regulation of gene expression B) Protection of genetic material C) Control of cellular transport D) Protein synthesis Answer: C) Control of cellular transport Rationale: The cell membrane regulates the passage of molecules in and out of the cell, maintaining cellular homeostasis and controlling cellular transport processes.

26. Which of the following structures is unique to eukaryotic cells and not found in prokaryotic cells? A) Nucleus B) Cell membrane C) Flagella D) Cell wall Answer: A) Nucleus Rationale: The nucleus is a membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material, which is absent in prokaryotic cells.
27. What is the function of the cytoskeleton in eukaryotic cells? A) Protein synthesis B) Cell motility and structural support C) ATP production D) Lipid synthesis Answer: B) Cell motility and structural support Rationale: The cytoskeleton is a network of protein filaments that provides structural support, shape, and movement within eukaryotic cells.
28. Which organelle is responsible for the breakdown of fatty acids and detoxification of harmful substances in eukaryotic cells? A) Peroxisome B) Lysosome C) Golgi apparatus D) Endoplasmic reticulum Answer: A) Peroxisome Rationale: Peroxisomes contain enzymes that break down fatty acids and detoxify harmful substances, such as hydrogen peroxide, in eukaryotic

cells.

29. Which of the following organelles is responsible for digesting cellular waste and foreign materials in eukaryotic cells? A) Lysosome B) Mitochondrion C) Golgi apparatus D) Chloroplast Answer: A) Lysosome Rationale: Lysosomes contain enzymes that break down cellular waste and foreign materials through the process of digestion in eukaryotic cells.
30. What is the main function of the endoplasmic reticulum in eukaryotic cells? A) Protein synthesis B) Energy production C) Lipid synthesis D) Genetic information storage Answer: C) Lipid synthesis Rationale: The endoplasmic reticulum plays a crucial role in lipid synthesis, protein modification, and detoxification in eukaryotic cells, serving as a manufacturing and packaging site within the cell.