The theory that living organisms on the earth came from outer space is based on the study of
Igneous rocks
Sedimentary rocks
Meteorites
Moon soil
All of the following conditions were present on early earth, except
Formation of which complex molecules was noticed by Urey and Miller when they subjected substances like $N{H_3},C{H_4},{H_2}O$ etc. to electric discharge
If you go back in the history approx. $4500$ million years back when atmosphere was reducing the organism were
The spark-discharge apparatus to test chemical evolution of life was designed by