Looking for classes? Ksquare Career Institute, Bengaluru →
Which of the following is a symbiotic nitrogen fixer?
A
$Azolla$
B
$Glomus$
C
$Azotobacter$
D
$Frankia$
Detailed Solution
$Frankia$ is a nitrogen-fixing microbe (an actinomycete) that produces nitrogen-fixing nodules on the roots of non-leguminous plants such as $Alnus$; it is a symbiotic nitrogen fixer.
$Azotobacter$ is a free-living aerobic nitrogen fixer of the soil.
$Glomus$ is a mycorrhizal fungus that helps in phosphorus absorption; it does not fix nitrogen.
$Azolla$ is a water fern; it does not fix nitrogen itself (the cyanobacterium $Anabaena$ living in its leaves does).
Hence the symbiotic nitrogen fixer is $Frankia$.
$Azotobacter$ is a free-living aerobic nitrogen fixer of the soil.
$Glomus$ is a mycorrhizal fungus that helps in phosphorus absorption; it does not fix nitrogen.
$Azolla$ is a water fern; it does not fix nitrogen itself (the cyanobacterium $Anabaena$ living in its leaves does).
Hence the symbiotic nitrogen fixer is $Frankia$.