Characteristics of the Nuclear Envelope Explained

Subject : Biology

Question:

What are characteristics of the nuclear envelope?

A. Is a double-layered porous membrane

B. Surrounds the entire cell contents

C. Separates the nuclear contents from the cytoplasm

D. Is attached to mitochondria

Expert Verified Solution:

The correct answer is A. Is a double-layered porous membrane and C. Separates the nuclear contents from the cytoplasm. Here’s a detailed explanation:

Double-Layered Porous Membrane (A): The nuclear envelope is composed of two lipid bilayers—an outer and an inner membrane. These layers are separated by a space known as the perinuclear space. The envelope has nuclear pores that allow selective exchange of materials between the nucleus and the cytoplasm.

Separates the Nuclear Contents from the Cytoplasm (C): The primary function of the nuclear envelope is to encase the nucleus, separating its contents, such as DNA and nucleoplasm, from the cytoplasm. This separation is crucial for maintaining the distinct environment required for proper DNA replication, transcription, and other nuclear processes.

Characteristics Not Correct:

Surrounds the Entire Cell Contents (B): The nuclear envelope does not surround the entire cell. It specifically encloses the nucleus within the cell.

Is Attached to Mitochondria (D): The nuclear envelope is not attached to mitochondria. Mitochondria are separate organelles within the cell, and the nuclear envelope is distinct from them.