. The abiotic synthesis of , such as amino acids and nitrogenous bases, may have occurred near volcanoes or around deep-sea vents. 2. The abiotic synthesis of may have occurred as organic monomers splashed onto hot rocks and spontaneously joined into chains. 3. The first may have formed when collections of organic molecules became isolated within membranes. 4. The first genetic material was probably self-replicating . 5. Once some protocells contained self-replicating molecules, could have begun to shape their properties as those that reproduced more efficiently would have increased in number. 6. At some point, , a more stable molecule, became the genetic material. 7. The earliest evidence of life on Earth is 3.5-billion-year-old fossils of , which were built up by ancient photosynthetic prokaryotes.

1. The abiotic synthesis of small organic molecules, such as amino acids and nitrogenous bases, may have occurred near volcanoes or around deep-sea vents.

2. The abiotic synthesis of polymers may have occurred as organic monomers splashed onto hot rocks and spontaneously joined into chains.

3. The first protocells may have formed when collections of organic molecules became isolated within membranes.

4. The first genetic material was probably self-replicating RNA.

5. Once some protocells contained self-replicating molecules, natural selection could have begun to shape their properties as those that reproduced more efficiently would have increased in number.

6. At some point, DNA, a more stable molecule, became the genetic material.

7. The earliest evidence of life on Earth is 3.5-billion-year-old fossils of Stromatolites, which were built up by ancient photosynthetic prokaryotes.

Explanation:

The points in the answer above are part of the description of events in the geological history of the formation of the earth and emergence life on earth.

The timeline for these events describes the formation of earth form the big bang, through evolution and extinction of various life forms on the earth.

common management practices in dairy and poultry farming are: (i) proper shelter facilities and their regular cleaning. (ii) some basic hygienic conditions such as clean water, nutritious food, etc. (iii) animals are kept in spacious, airy, and ventilated place.