Question

All kinds of living beings, except human beings directly originated from non-living matter was the theory of
A. Panspermia
B. Biogenesis
C. Abiogenesis
D. None of the above

Answer 1

Hint: Life originated on earth million years ago and since then innumerable varieties of living organisms have been originated leading to a wide number of theories.

Complete answer:
Abiogenesis is the generation of life forms from non-living matter. According to the theory of abiogenesis, complex living organisms are generated from decaying organic substances e.g. organisms like mice spontaneously appear in stored grain or maggots spontaneously appear in meat. The theory of abiogenesis is also termed as the theory of spontaneous generation or auto biogenesis.
Several scientists disapproved of this theory. A few examples have been stated below.
By conducting a simple experiment, Italian physician Redi demonstrated that abiogenesis can not exist.

From these observations, he concluded that life arises from the eggs laid down by the flies and the maggots cannot appear spontaneously.
Spallanzani’s experiment: According to him, air carries microorganisms, which germinate when they get moisture or food. This proved abiogenesis does not exist.
Pasteur’s Experiment: His experiments revealed that only minute organisms can arise from pre-existing organisms. The life can not arise spontaneously under Earth’s conditions.

The theory of Biogenesis states that living things come from other living things. For example mice come only from mice, and microorganisms such as bacteria can come from other bacteria.
The theory of Panspermia states that life is distributed throughout the cosmos in the form of resistant spores, the cosmozoa. They reached Earth accidentally from some other planet. On getting favorable conditions for life, they developed into an organism and evolved into existing forms.
So, the correct answer is ‘Abiogenesis’.

Note: - The theory of abiogenesis was believed and supported by Thales, Anximander, Newton, and Descrates.
- The theory of Panspermia was put forward by Richter and supported by Arrhenius and others.