The correct sequence of processes in the nitrogen cycle is:
1. Organic nitrogen formation: Incorporation of ammonia into organic molecules.
2. Soil organic nitrogen formation: Conversion of organic nitrogen into soil compounds.
3. Ammonia formation: Conversion of atmospheric nitrogen into ammonia.
4. Nitrate formation: Oxidation of ammonia and organic nitrogen into nitrates.
Correctly match the enzymes used as selectable markers (Group I) and the chemicals used for their selection (Group II):
Correctly match the economically important specialized metabolites (Group I) with their broad chemical classes (Group II):