Question

1-How did life originate? What were the likely circumstances surrounding the origin of life? What evidence do we have of when and how it originated? Where did this likely happen?

2-What are the main issues faced in the spontaneous origin of life, and what are some ways that they may be resolved?

Answer 1

Ans1 The present theory of living things came from is called biogenesis. The theory states that living things come only from other living things.

For example mice come only from mice, and microorganisms such as bacteria can only come from other bacteria.

Evidence of how life started on earth, were first given by the scientists Oparin and Haldane. The proposed their theory as chemical evolution.

The Oparin-Haldane model suggested that under the strong reducing conditions theorized to have been present in the atmosphere of the early earth, inorganic molecules food spontaneously form organic molecules ( simple sugars and amino acids).

Oparin argued that primeval soup of organic molecules could be created in an oxygenless atmosphere through the action of sunlight.

Around the same time, Haldane proposed that the earth's prebiotic oceans would have formed a hot dilute soup in which organic compounds could have formed.

Ans 2) Abiogenesis is the generation of life from nonliving matter. Abiogenesis is also known as spontaneous origin of life.

This theory states that complex living organisms are generated from decaying organic substances example organism like mice spontaneously appeared in stored grain or maggots spontaneously appear in meat.

Francesco Redi, was the first scientist who disproved the theory of spontaneous generation. He performed an experiment and concluded that the maggots did not come from the meat, but from tiny eggs that flies had laid on the meat.

Finally Louis Pasteur disproved the spontaneous origin of life with his experiments on two flasks- one with straight neck and other with S- shaped neck.

Scientists finally were convinced that living things, no matter how small, do not come from non living things.

This was resolved the present theory of biogenesis. This theory states that living things come from other living things.

Ps- A positive rating would be highly appreciated

Thanks