Photosynthesis in Higher Plants — BIOLOGY STD 11 Science — Question

4. Inorganic chemicals.

Explanation:

Chemosynthetic autotrophic bacteria (chemoautotrophic bacteria) are bacteria which are able to manufacture their organic food from inorganic raw materials with the help of energy derived from exergonic chemical reactions involving oxidation of an inorganic substance present in the external medium. The chemical energy obtained from oxidation reaction is trapped in ATP molecules. They play a great role in recycling nutrients like nitrogen, phosphorous, iron and sulphur. There are several types of chemoautotrophic bacteria but the well known examples are nitrifying bacteria, sulphur oxidising bacteria, and iron bacteria.