During bacterial conjugation, DNA is transferred through a:
Pilus
Capsule
Flagellum
The Correct Answer is A
A. Pilus: During bacterial conjugation, a specialized structure called a sex pilus (or conjugation pilus) forms a direct connection between two bacterial cells. The donor cell transfers a copy of plasmid DNA or other genetic material through this pilus to the recipient cell, allowing for horizontal gene transfer and the spread of traits such as antibiotic resistance.
B. Capsule: The bacterial capsule is a polysaccharide layer that surrounds the cell wall and provides protection against phagocytosis and desiccation. It does not play a role in the transfer of DNA between bacterial cells, and therefore is not involved in conjugation.
C. Flagellum: The flagellum is a whip-like appendage that enables bacterial motility. While important for movement and chemotaxis, it is not used for DNA transfer during conjugation. DNA exchange occurs specifically through the pilus, not through flagella.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
A. Positive-sense RNA: Positive-sense RNA viruses possess genomes that function directly as messenger RNA (mRNA). After entering the host cell, the viral RNA can immediately bind to host ribosomes and begin translation to produce viral proteins. No transcription step is required before protein synthesis, these viruses can rapidly initiate replication once infection occurs.
B. Negative-sense RNA: Negative-sense RNA viruses have genomes that are complementary to mRNA and therefore cannot be translated directly by host ribosomes. Before protein synthesis can occur, the virus must first use an RNA-dependent RNA polymerase to synthesize a complementary positive-sense RNA strand. Only this newly formed RNA can function as mRNA for protein production.
C. Double-stranded RNA: Double-stranded RNA viruses contain both a positive and a negative RNA strand. However, the host cell cannot directly translate the double-stranded genome. The virus must first use viral RNA polymerase enzymes to transcribe the negative strand into a positive-sense RNA that can serve as mRNA for translation.
Correct Answer is B
Explanation
A. Protozoa: Protozoa are single-celled eukaryotic organisms. They have a true nucleus and membrane-bound organelles, distinguishing them from prokaryotes. Examples include Plasmodium and Giardia.
B. Bacteria: Bacteria are prokaryotic organisms, meaning they lack a membrane-bound nucleus and organelles. Their genetic material exists in a nucleoid, and their cellular processes occur in the cytoplasm or at the plasma membrane. This simplicity allows rapid growth and adaptation.
C. Fungi: Fungi are eukaryotic organisms, including yeasts and molds. They possess a true nucleus, 80S ribosomes, and membrane-bound organelles. Their complex cellular structures differentiate them from prokaryotes.
D. Algae: Algae are eukaryotic photosynthetic organisms. They contain chloroplasts, a nucleus, and other organelles. While some are unicellular, their cellular organization classifies them as eukaryotic, not prokaryotic.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.