Which of the Following is a Defining Characteristic That All

Question

Which of the following is a defining characteristic that all protobionts had in common?
A) the ability to synthesize enzymes
B) a surrounding membrane or membrane-like structure
C) RNA genes
D) the ability to replicate RNA

Accepted Answer

A surrounding membrane or membrane-like structure is a defining characteristic that all protobionts had in common. Protobionts are considered as the first step towards the formation of cells, and they are defined by their self-assembled structures that possess a selectively permeable membrane. This membrane-like structure provided separation from the external environment and allowed for the exchange of materials essential to life, such as nutrients and waste. Enzyme synthesis, RNA genes, and RNA replication are not necessarily defining characteristics of protobionts.