Nucleus Structure in Eukaryotic Cell

Questions and Answers

What is the primary function of the nucleus in a eukaryotic cell?

To generate energy for the cell

To contain the genetic material of the cell (correct)

To regulate cell growth

To synthesize proteins

How many separate membranes surround the nucleus?

Three

One

Two (correct)

Four

What is the fluid-filled space inside the nucleus called?

Nucleoplasm (correct)

Cytoplasm

Mitochondrial matrix

Endoplasmic reticulum

Why are nuclear pores important?

They allow for transportation of compounds between the cytoplasm and nucleus Signup and view all the answers

Where is messenger RNA (mRNA) produced?

In the nucleoplasm Signup and view all the answers

What passes through the nuclear pore?

Compounds like mRNA and proteins Signup and view all the answers

What is the purpose of the outer and inner membranes surrounding the nucleus?

To separate the nucleus from the cytoplasm Signup and view all the answers

What is true about the cytoplasm and nucleoplasm?

They are separate fluid-filled spaces Signup and view all the answers

What is the primary function of the nucleus?

To contain the cell's DNA, or chromosomes Signup and view all the answers

What is the nucleolus primarily responsible for?

Assembling ribosomes Signup and view all the answers

What type of RNA is produced in the nucleolus?

Ribosomal RNA Signup and view all the answers

Why is the nucleolus more compact and dense than the rest of the nucleus?

Because it is the site of ribosome assembly Signup and view all the answers

What is the term for the combination of the inner and outer nuclear membranes along with the nuclear pores?

Nuclear envelope Signup and view all the answers

What is the purpose of the nuclear pore?

To regulate the transport of molecules in and out of the nucleus Signup and view all the answers

What is unique about the outer nuclear membrane?

It is continuous with the endoplasmic reticulum membranes Signup and view all the answers

What is the significance of the nuclear envelope?

It separates the nucleus from the cytoplasm Signup and view all the answers

Study Notes

Nucleus Structure

The nucleus is surrounded by two separate membranes: an outer membrane and an inner membrane, which separate it from the cytoplasm.
The cytoplasm is the liquid-filled space that makes up the majority of the cell, and the nucleoplasm is the fluid inside the nucleus.
The cytoplasm and nucleoplasm are not continuous, but transport of materials between them occurs through nuclear pores.

Nuclear Pores

Nuclear pores are special complexes that span both membranes, allowing compounds in the cytoplasm to be transported into the nucleus and vice versa.
Nuclear pores are selective and recognize special signals on proteins, allowing only certain proteins to be transported in and out of the nucleus.

Nucleolus

The nucleolus is a densely compacted area within the nucleus, where ribosome assembly takes place.
The nucleolus is the site of ribosomal RNA production, and it assembles with proteins to form fully-formed ribosomes.
Ribosomes are then trafficked through the nuclear pore into the cytoplasm.

Nuclear Envelope and Endoplasmic Reticulum

The outer membrane of the nucleus is continuous with the membranes of the endoplasmic reticulum.
The interior space of the endoplasmic reticulum is continuous with the space between the outer and inner nuclear membranes.
The nuclear envelope refers to the combination of the inner and outer membranes along with the nuclear pores.