#Question id: 40225
#Applied Microbiology
Read the following statements regarding cloning vectors and select the correct option.
Statement I: Antibiotic resistance markers are essential for an expression vector but not necessary for a standard cloning vector.
Statement II: The presence of an antibiotic resistance gene allows transformed bacteria to survive on media containing the corresponding antibiotic.
#Question id: 40226
#Applied Microbiology
Assertion (A): When plating bacteria after a transformation experiment, adding ampicillin to the agar plates is crucial if the plasmid vector carries the ampR gene.
Reason (R): Ampicillin acts as a nutrient source for the bacteria that have successfully taken up the plasmid.
#Question id: 40227
#Applied Microbiology
Which of the following microorganisms is a free-living, aerobic, chemoorganotrophic nitrogen fixer?
#Question id: 40228
#Applied Microbiology
Consider the following statements regarding nitrogen-fixing bacteria:
Statement I: Rhizobium forms a symbiotic association with leguminous plants and fixes nitrogen only within the root nodules.
Statement II: Alcaligenes species are primarily known as anaerobic chemolithotrophs in the nitrogen cycle.
#Question id: 40229
#Applied Microbiology
Assertion (A): Photosynthetic bacteria like Rhodobacter can fix atmospheric nitrogen.
Reason (R): These bacteria possess the nitrogenase enzyme complex, which is sensitive to oxygen.
#Question id: 40230
#Applied Microbiology
Match the specialized structures/enzymes with the corresponding nitrogen fixer:
| List-I (Structure/Enzyme) | List-II (Microorganism) |
| (A). Heterocyst | (I). Rhizobium |
| (B). Leghaemoglobin | (II). Anabaena |
| (C). Respiratory Protection | (III). Clostridium |
| (D). Anaerobic N-fixation | (IV). Azotobacter |