BIOLOGY IN HUMAN WELFARE
MICROBES IN HUMAN WELFARE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
A, C, D
|
|
|
C, D
|
|
|
A, C
|
|
|
A, B C
|
Detailed explanation-1: -Anabaena is a cyanobacterium or blue-green algae. It can fix atmospheric nitrogen. They have specialized cells for nitrogen fixation called heterocysts.
Detailed explanation-2: -In the sea, turbulence from wave action apparently separates trichomes allowing O2 to enter thus decreasing nitrogenase activity. These observations explain how Oscillatoria is able to fix N2 without heterocysts in an aerobic environment and why its blooms virtually always occur in calm seas.
Detailed explanation-3: -a symbiotic association with cyanobacteria Anabaena for Nitrogen fixation. and does fulfill the need for nitrogen by the plant itself. So, the answer is ‘Nostoc, Anabaena, Oscillatoria’.
Detailed explanation-4: -Anabaena, Nostoc and Oscillatoria are nitrogen fixing cyanobacteria (Blue Green algae) while Azobacter and Azospirillum are nitrogen fixing free living bacteria.