Which of these is NOT a characteristic feature of the root nodules formed during legume-rhizobia symbiosis?
Presence of chloroplasts in bacteroids
Presence of leghemoglobin
Differentiated bacteroids
Reduced oxygen concentration
Related Questions
Which of the following is NOT a direct consequence of Nod factor signaling in the host plant during root nodule formation?
Root hair curling
Formation of infection threads
Cortical cell division leading to nodule primordia formation
Expression of nif genes in bacteroids
What is the primary benefit for leguminous plants in forming root nodules with nitrogen-fixing bacteria?
Increased water absorption
Protection from pathogens
Access to usable nitrogen
Enhanced photosynthesis
Which statement is TRUE regarding the protection of nitrogenase from oxygen?
Nitrogenase is insensitive to oxygen.
Oxygen promotes nitrogenase activity.
Leghaemoglobin binds with oxygen in root nodules.
Nitrogen fixation occurs best in aerobic conditions.
Nitrogenase, the enzyme responsible for converting atmospheric nitrogen to ammonia, is susceptible to inactivation by oxygen. How do free-living nitrogen-fixing bacteria like Azotobacter protect nitrogenase from oxygen?
Leghaemoglobin production
Symbiotic relationships with plants
High respiration rate
Formation of specialized cells
The sensitivity of nitrogenase to oxygen necessitates protective mechanisms. Which of the following is NOT a strategy employed by nitrogen-fixing organisms to protect nitrogenase?
Producing leghaemoglobin
Maintaining a high respiration rate
Forming specialized heterocysts
Performing photosynthesis in the same cells as nitrogen fixation
Bacteria and fungi developing on dead decaying organisms are
Parasites
Commensals
Saprophytes
Symbionts
A researcher observes that a particular legume mutant forms nodules, but these nodules fail to fix nitrogen. Which of the following gene mutations is MOST likely responsible?
Mutation in nod genes
Mutation in genes encoding flavonoid biosynthesis
Mutation in nif genes
Mutation in genes encoding leghemoglobin
Which specific flavonoid is known to induce nod gene expression in Rhizobium leguminosarum when establishing symbiosis with pea plants?
Naringenin
Apigenin
Kaempferol
Luteolin
Which two important amides found in the plants are structural part of proteins
Glutamate and ureides
Glycine and serine
Glutamine and asparagine
Asparagine and arginine
The product of reaction catalyzed by nitrogenase in root nodules of leguminous plants
Ammonia alone
Nitrate alone
Ammonia and oxygen
Ammonia and hydrogen
