Question

The organism which is autotrophic but does not have the pigment is

• A. Nostoc
• B. Wolffia
• C. Yeast
• D. Nitrosomonas

Answer 1

The correct option is D

Nitrosomonas

The correct option is D.

Explanation of the correct option:

1. Nitrosomonas do not undergo photosynthesis because they lack chlorophyll.
2. They convert ammonia to nitrite.
3. Further, Nitrobacter converts nitrite into nitrate.

Explanation of the incorrect options:

Option A:

Nostoc is a photoautotroph that has pigments that also fix atmospheric nitrogen.

Option B:

Wolffia is a photoautotroph that has pigments.

Option C:

Yeast is a fungus that feeds on dead and decaying matter.

Final answer: The organism which is autotrophic but does not have the pigment is Nitrosomonas.