Certain mutant legumes exhibit excessive root hair curling in the presence of rhizobia, but infection threads fail to penetrate the cortex. This phenotype is MOST likely due to a defect in:
Flavonoid production by the root
Rhizobial nod gene expression
Nod factor receptor function
Signaling pathway downstream of Nod factor perception, affecting infection thread growth
Related Questions
The function of leghaemoglobin in the root nodules of legumes is
Oxygen removal
Nodule differentiation
Expression of nif gene
Inhibibition of nitrogenase activity
Leghemoglobin, present in root nodules, plays a crucial role in nitrogen fixation by:
Protecting nitrogenase from oxygen
Providing oxygen to nitrogenase
Converting nitrogen to ammonia
Transporting nitrogen to bacteroids
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 relationship between Rhizobium bacteria and leguminous plants is an example of:
Parasitism
Commensalism
Symbiosis
Predation
In root nodules of legumes, leghaemoglobin is important because it
Transports oxygen to the root nodule
Acts as an oxygen scavenger
Provides energy to the nitrogen fixing bacterium
Acts as a catalyst in transamination
Root nodules are primarily found in which part of the plant?
Stems
Leaves
Flowers
Roots
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 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.
VAM is
Ectomycorrhizae
Endomycorrhizae
Both (a) and (b)
Ectoendomycorrhizae
