Question

(A) Which structure is not a part of the endomembrane system?

(B) Nuclear membrane

(C) Golgi apparatus

(D) Chloroplast

(E) Plasma membrane

Short answer

(A) The option “nuclear membrane” is incorrect.

(B) The option “Golgi apparatus” is incorrect.

(C) The option “chloroplast” is correct.

(D) The option “plasma membrane” is incorrect.

Step-by-step solution

Organelle

An organelle is a subunit of a cell that performs a particular role. Organelles that are individually enveloped in the membrane are termed membrane-bound organelles.

Organelles that are distinct functional units without an enclosing lipid bilayer are known as non-membranous organelles.

Explanation for option ‘(A)’

The nuclear membrane is the membrane present outside the nucleus and is in direct contact with the cytoplasm. A double-membrane structure surrounds the nucleus.

The space between two nuclear membranes is called perinuclear space; it also contains nuclear pores for transportation purposes. It is present as the portion of the endomembrane system.

Thus, the option is incorrect.

Explanation for option ‘(B)’

The Golgi body or Golgi apparatus is involved in packaging the proteins and lipids and then modifying and transporting them to other parts of the cell.

It is also involved in the transportation of the lipids encompassing the cell and the production of lysosomes. It also forms the part of the endomembrane system.

Thus, the option is incorrect.

Explanation for option ‘(C)’

Chloroplast is a double-membrane structure having its genetic material with circular DNA and the 70S-type ribosome. They are not part of the endomembrane system.

Thus, the option is correct.

Explanation for option ‘(D)’

The plasma membrane is the term used to define the delimiting or defining structure surrounding the cell’s cytoplasm in both prokaryotic and eukaryotic organisms, which is involved in transportation. The endomembrane system includes this as its part.

Thus, the option is incorrect.