Assertion : The first living organisms on earth were autotrophs.
Reason : They were capable of performing chemosynthesis.

The first organisms appeared on earth were

The first organisms appeared on earth were

The first organism on earth were thought to be

The first organism on earth were thought to be

The first organisms were:

Assertion : The first living organisms were heterotrophs. Reason : The were surrounded by preformed organic molecules which they used as food

The first organisms were

The first organism were