Basic Microbiology

Which of the following is/are TRUE about the Escherichia coli chromosome? (A) It is typically bound by histones (B) It is circular in nature (C) It is found in the nucleoid (D) It contains multiple origins of replication  

At root nodules, which of the following C4 organic acid(s) is/are transported across the symbiosome membrane and into bacteroids? (A) Succinate (B) Pyruvate (C) Malate (D) Fumarate  

Which of the following is/are consequence(s) of nitrous acid (HNO2_22​) mediated deamination? (A) Deamination of cytosine, adenine, and guanine (B) GC-to-AT transitions (C) AT-to-GC transitions (D) Addition of an alkyl group to the bases  

Which of the following event(s) occur(s) during translation in prokaryotes? (A) tRNA binding to the start codon of mRNA on the 30S subunit of the ribosome (B) Anticodon of tRNA binding to the start codon of mRNA on the 50S subunit of the ribosome (C) The ribosome continues to move along the mRNA to add … Read more

Which of the following cocci is/are examples of division in one plane? (A) Staphylococci (B) Streptococci (C) Micrococci (D) Diplococci  

Which of the following is/are active transport mechanism(s) in prokaryotes where the substance is chemically altered during transport across the membrane? (A) Group translocation (B) Simple diffusion (C) Facilitated diffusion (D) Osmosis  

Which one of the following redox couples has the highest tendency to donate electrons? (A) Fumarate / succinate (B) NAD+^++ / NADH (C) FAD / FADH2_22​ (D) Pyruvate / lactate  

Match the antibiotics in Group I with the microorganisms that produce them in Group II. Group I Group II (P) Streptomycin (i) Streptomyces griseus (Q) Bacitracin (ii) Bacillus licheniformis (R) Amphotericin B (iii) Streptomyces nodosus (S) Chloramphenicol (iv) Streptomyces venezuelae (A) (P)-(ii), (Q)-(iii), (R)-(i), (S)-(iv) (B) (P)-(i), (Q)-(ii), (R)-(iii), (S)-(iv) (C) (P)-(i), (Q)-(ii), (R)-(iv), (S)-(iii) … Read more

Which one of the following represents the abundance of the organisms found in soil? (A) Fungi > Aerobic bacteria > Anaerobic bacteria (B) Aerobic bacteria > Fungi > Anaerobic bacteria (C) Aerobic bacteria > Anaerobic bacteria > Fungi (D) Anaerobic bacteria > Aerobic bacteria > Fungi  

Which one of the following uses inorganic compounds as an energy source? (A) Heterotrophs (B) Chemolithotrophs (C) Chemoorganotrophs (D) Photoheterotrophs