Which of the following infects new leaves of Azolla as they develop from the stem during nitrogen fixation?
a) Azotobacter
b) Clostridium
c) Rhizobium
d) Anabaena azollae
Explanation: Anabaena azollae is a cynobacteria
Nitrogen fixing bacteria contain which of the following enzyme complex?
a) amylase
b) nitrogenase
c) denitrogenase
d) amino-aceyl transferase
Rhizobium contains…….which binds with oxygen?
a) hemoglobin
b) myoglobin
c) leghaemoglobin
d) albumin
Explanation: Leghemoglobin is an oxygen-carrying phytoglobin found in the nitrogen-fixing root nodules of leguminous plants.
Ammonification is the process of ……..
a) formation ammonia from nitrogen by nitrogen fixers
b) formation of ammonia from nitrates by nitrogen fixers
c) formation of ammonia from amino acid by decomposers
d) formation of ammonia from nitrates by decomposers
Explanation: When an organism excretes waste or dies, the nitrogen in its tissues is in the form of organic nitrogen (e.g. amino acids, DNA). Various fungi and prokaryotes then decompose the tissue and release inorganic nitrogen back into the ecosystem as ammonia in the process known as ammonification.
The
oxidation of ammonium compounds to nitrates and then to nitrites is called…
a) ammonification
b) nitrification
c) Denitrification
d) nitrogen fixation
Explanation: it is done by nitrifying bacteria
Nitrification occurs in well drained and aerated soil at…….
a) neutral pH
b) acidic pH
c) basic pH
d) both b and c
