Question

Which organism is not made up of cells that each contain a membrane-enclosed nucleus?

A) possum
B) bacterium
C) mushroom
D) paramecium

Answer 1

D. Methanogen 

Which organism is NOT made up of cells that each contain a membrane-enclosed nucleus? 
B. bacterium 
Somewhat evil question. Try not to think about mammalian red blood cells. 

Which type of organism is a prokaryote? 
D. bacterium 

Which organism is a prokaryote? 
A. bacterium

Answer 2

Answer:

B) bacterium

Explanation:

• The organisms which lack a membrane-enclosed nucleus and other membrane-bound organelles are known as prokaryotes.
• Prokaryotes are unicellular organisms and their nucleus is not a true nucleus as it lacks the membrane and is termed as a nucleoid.
• From the given list, the bacterium is a prokaryote and hence it lacks a membrane-bound nucleus.