Fact 1: Some viruses have an envelope of phospholipids and proteins.

Fact 2: Viruses are enveloped by similar membranes.

Given the two facts above, answer the question "What have similar membranes?" with the following options: 
- PDAs
 - humans
 - viruses
 - crocodiles
 - animals
 - sharks
 - fur seals
 - insects


 

   viruses      