Who proved that life comes from pre-existing life?

Formation of which complex molecules was observed by Urey and Miller when they subjected substances like $NH_3, CH_4, H_2O$ and $H_2$ to electric discharge?

According to Oparin,which one of the following was absent in the primitive atmosphere of the Earth?

Which of the following experiments suggested that the simplest living organisms could not have originated spontaneously from non-living matter?

According to conventional religious literature,how old is the Earth?

Seed ferns originated in