Question

The first cell produced on earth is
A)Protobiont
B)Protozoa
C)Metazoa
D)None of the above

Answer 1

Hint: The primitive earth contained hot gases which were produced by the eruption of the volcanos. The methane, hydrogen, carbon, nitrogen etc interacted upon each other and produced the first living form that was capable of performing photosynthesis.

Complete answer:
The origin of life is considered as the most complex process which took place over billions of years ago. It is believed that life originated by several natural processes which converted the non-living matter into simple organic compounds. The living body is also made up of several organic compounds which work in coordination and support the various physiological activities.

It is believed that the life originated from the inorganic molecules like carbon, nitrogen, methane, hydrogen under the conditions of pressure and temperature and got converted into organic molecules which gave rise to early protobionts.
The Protobionts are considered as the precursor of the prokaryotic cell. These are proteinoid based protocells in which the genetic material RNA was present. It is a simple cluster of organic molecules which is capable of reproduction and carries out certain physiological processes like the living cells.

1)Protozoa- They are single celled eukaryotes which live as parasites or are free living.
2)Metazoa- They are multicellular eukaryotic organisms. It comprises all the animals on the seafloor.

Hence, the correct answer is option (A)

Note: The first primitive organism is said to be evolved around 3.5-2 billion years ago. The precursor protocells might have used the molecules present on the earth for the growth and multiplication. Slowly the organisms produced all the essential nutrients needed for growth and development. This led to the evolution of advanced species.