You are presented with the question "What do some bacteria lack?" and the following answer choices: 
- Energy
 - nucleus
 - glucose
 - Energy.
 - properties
 - oxygen
 - alleles
 - warmth

Now knowing that prokaryotes are single-celled organisms that lack a nucleus and prokaryotes are usually microscopic and bacteria is an example of a prokaryote, choose the best answer.


 

  nucleus       