Which of the following pair lack the unit membrane:-
Nucleus & E. R.
Mitochondria & chloroplast
Ribosome & nucleolus
Golgi body & Lysosome
The correct option is C Ribosome & nucleolus
Nucleus has the outer nuclear membrane which is attached to the rough endoplasmic reticulum. This membrane is towards the outer side of the cell while the endoplasmic reticulum has a double-layered plasma membrane.
Mitochondria and chloroplasts have double membranes which help to protect their respective DNA.
The Golgi body and Lysosome has enzymes for digestion of proteins, lipids etc in the unit membrane.
Ribosomes lack the unit membrane. They are present individually in the cell cytoplasm and make the lining of the rough endoplasmic reticulum.
Nucleolus lacks a unit membrane. They have genetic materials in the nucleus which consists of RAN, DNA, proteins etc.
So, the correct option is 'Ribosome and nucleolus'.