Quiz on Prokaryotic Cells

Quiz on Prokaryotic cells 1. What is a unique feature of prokaryotic DNA compared to eukaryotic DNA? A. It is found in a membrane-bound nucleus. B. It does not contain any plasmids. C. It is typically a single circular chromosome. D. It exists as multiple linear chromosomes. Answer: It is typically a single circular chromosome. (C) Prokaryotic DNA is generally organized as a single circular chromosome, unlike the multiple linear chromosomes found in eukaryotes. 2. Which process allows prokaryotes to exchange genetic material, contributing to traits such as antibiotic resistance? A. Mutation B. Transcription C. Conjugation D. Binary fission Answer: Conjugation (C) Conjugation is the process by which plasmids are exchanged between bacteria, playing a key role in the rapid evolution of antibiotic resistance. 3. How do prokaryotes contribute to the nitrogen cycle? A. By decomposing inorganic matter into nitrogen. B. By limiting the growth of eukaryotic species. 2 C. By directly converting nitrogen into oxygen. D. By transforming nitrogen into forms usable by plants. Answer: By transforming nitrogen into forms usable by plants. (D) Prokaryotes play an essential role in transforming atmospheric nitrogen into forms that are usable by plants, significantly influencing agricultural productivity. 4. What is the primary mode of reproduction for prokaryotes? A. Mitosis B. Binary fission C. Meiosis D. Budding Answer: Binary fission (B) Prokaryotes mainly reproduce asexually through binary fission, allowing for rapid colonization of their environments. 5. What role do prokaryotes play in biotechnology? A. They produce useful chemicals and medicine. B. They hinder the production of pharmaceuticals. C. They have no significant applications in biotechnology. D. They only serve as contaminants in lab settings. Answer: They produce useful chemicals and medicine. (A) Prokaryotes are foundational to biotechnology, as they can produce a variety of useful chemicals and medicine based on their metabolic processes. 6. What is a key structural difference between the cell walls of 3 bacteria and archaea? A. Bacteria have a rigid phospholipid bilayer . B. Bacteria have a cell wall composed of peptidoglycan. C. Archaea have a cell wall made of peptidoglycan. D. Archaea have cell walls made exclusively of proteins. Answer: Bacteria have a cell wall composed of peptidoglycan. (B) The composition of the cell wall is crucial for classification; bacteria have peptidoglycan, while archaea have various polysaccharides and proteins. 7. Which prokaryotic structure is primarily involved in protein synthesis? A. Cell membrane B. Flagella C. Nucleoid D. Ribosomes Answer: Ribosomes (D) Ribosomes are the sites of protein synthesis, differing in size and structure from those in eukaryotic cells. 8. What is the role of pili (fimbriae) in prokaryotic cells? A. To provide structure and protection. B. To regulate the passage of substances in and out of the cell. C. To attach to surfaces or transfer genetic material. D. To allow movement through the environment. Answer: To attach to surfaces or transfer genetic material. (C) 4 Pili are hair-like appendages used by prokaryotes for attachment and conjugation. 9. Which metabolic process is performed by some prokaryotes and is crucial for nutrient cycling? A. Nitrogen fixation B. Fermentation C. Photosynthesis D. Aerobic respiration Answer: Nitrogen fixation (A) Nitrogen fixation is essential for converting atmospheric nitrogen into ammonia, vital for nutrient cycling. 10. Which domain of prokaryotic life is recognized for thriving in extreme environments? A. Archaea B. Bacteria C. Protista D. Eukarya Answer: Archaea (A) Archaea are known for their ability to survive in extremely harsh conditions. 11. What distinguishes prokaryotic cells from eukaryotic cells regarding their genetic material? A. Prokaryotic cells have linear DNA. B. Prokaryotic cells have membrane-bound DNA. 5 C. Prokaryotic cells have a true nucleus. D. Prokaryotic cells contain circular DNA located in the nucleoid. Answer: Prokaryotic cells contain circular DNA located in the nucleoid. (D) Prokaryotic cells have circular DNA housed in the nucleoid, unlike the linear DNA in eukaryotic cells. 12. Which statement best describes the differences in flagella between prokaryotes and eukaryotes? A. Eukaryotic flagella consist entirely of peptidoglycan. B. Prokaryotic flagella have a different structure and mechanism of movement. C. Prokaryotic flagella are larger and more complex. D. Eukaryotic flagella are simpler in structure than prokaryotic flagella. Answer: Prokaryotic flagella have a different structure and mechanism of movement. (B) Prokaryotic flagella differ in both structure and function compared to those in eukaryotic cells. 13. Which of the following is NOT a characteristic of prokaryotic cells? A. Ubiquitous in various environments B. Lack of membrane-bound organelles C. Smaller size than eukaryotic cells D. Presence of a nucleus Answer: Presence of a nucleus (D) 6 Prokaryotic cells are defined by the absence of a nucleus and membrane-bound organelles.