Which scientist permanently disproved the theory of spontaneous generation?

Which was absent in the atmosphere at the time of origin of life?

Organic compounds first evolved on Earth,which were required for the origin of life,were:

Assertion: The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
Reason: The first autotrophic organisms were the chemoautotrophs that never released oxygen.

The proponent of the theory of spontaneous generation was

Define and explain the terms $Abiogenesis$ and $Biogenesis$.