Nucleus and Nuclear Envelope: Structure and Function | Cell Biology

Question 1

Which of the following describes the structure of the nuclear envelope?

Accepted Answer

A double membrane surrounding the nucleus

Answer

A single membrane allowing free movement of molecules

Answer

A membrane without pores, preventing material exchange

Answer

A single layer of phospholipids

Question 2

In the nucleus, which structure is responsible for producing ribosomes?

Accepted Answer

Nucleolus

Answer

Nuclear membrane

Answer

Nuclear matrix

Question 3

Which of the following is NOT a function of the nuclear envelope?

Accepted Answer

Contains ribosomes for protein synthesis

Answer

Provides structural support to the nucleus

Answer

Regulates the exchange of materials between the nucleus and cytoplasm

Answer

Protects the genetic material from damage

Question 4

Which of the following is NOT a function of the nuclear envelope?

Accepted Answer

Containing ribosomes for protein synthesis

Answer

Regulating the movement of materials between the nucleus and cytoplasm

Answer

Protecting the genetic material from damage

Answer

Providing structural support to the nucleus

Question 5

Which of the following is NOT a function of the nuclear envelope?

Accepted Answer

Facilitates the translation of mRNA into proteins

Answer

Regulates the exchange of materials between the nucleus and the cytoplasm

Answer

Protects the genetic material

Answer

Facilitates the transcription of DNA into RNA

Question 6

Which structure inside the nucleus is responsible for manufacturing ribosomes?

Accepted Answer

Nucleolus

Answer

Mitochondria

Answer

Lysosome

Answer

Endoplasmic reticulum

Question 7

What type of chromatin is actively involved in gene expression?

Accepted Answer

Euchromatin

Answer

Heterochromatin

Answer

Nucleolus

Answer

Nuclear matrix

Question 8

Which protein complex is responsible for unwinding the DNA double helix during transcription?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Transcription factors

Answer

RNA polymerase

Question 9

What is the name of the modified nucleoside that is added to the 5' cap of eukaryotic mRNAs?

Accepted Answer

7-methylguanosine

Answer

Guanine

Answer

Adenine

Answer

Uridine

Question 10

What is the primary function of the nuclear lamina?

Accepted Answer

Providing structural support to the nucleus

Answer

Regulating gene expression

Answer

Mediating protein synthesis

Answer

Transporting materials across the nuclear envelope

Question 11

Which enzyme is responsible for joining the Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Answer

DNA polymerase

Answer

RNA polymerase

Answer

Primase

Question 12

What is the process by which the nuclear envelope breaks down during cell division called?

Accepted Answer

Nuclear envelope breakdown

Answer

Karyokinesis

Answer

Cytokinesis

Answer

Nuclear export

Question 13

Which of the following is NOT a common nuclear abnormality associated with cancer?

Accepted Answer

Diploidy

Answer

Polyploidy

Answer

Aneuploidy

Answer

Hypoploidy

Question 14

During cell division, what significant structural changes occur in the nuclear envelope?

Accepted Answer

The nuclear envelope breaks down during prophase and reforms in telophase.

Answer

The nuclear envelope remains intact throughout cell division.

Answer

The nuclear envelope breaks down during metaphase and reforms in anaphase.

Answer

The nuclear envelope remains intact during mitosis but breaks down during meiosis.

Question 15

What is the primary component of the nuclear pore complex?

Accepted Answer

Nucleoproteins

Answer

Phospholipids

Answer

Carbohydrates

Answer

Lipids

Question 16

Which of the following processes occurs within the nucleolus?

Accepted Answer

RNA processing

Answer

DNA replication

Answer

Transcription

Answer

Protein synthesis

Question 17

What is the role of heterochromatin in gene expression?

Accepted Answer

Inactive regions of DNA transcription

Answer

Active regions of DNA transcription

Answer

Contains genes that are essential for cell survival

Answer

Protects chromosomes from damage

Question 18

Which of the following technologies allows us to visualize the distribution of specific proteins within the nucleus?

Accepted Answer

Immunofluorescence microscopy

Answer

Polymerase chain reaction (PCR)

Answer

Flow cytometry

Answer

Gel electrophoresis

Question 19

What is the primary role of the nuclear lamina?

Accepted Answer

Provides structural support to the nucleus

Answer

Facilitates DNA replication

Answer

Regulates gene expression

Answer

Protects the nucleus from oxidative damage

Question 20

What is the significance of nuclear localization signals (NLSs)?

Accepted Answer

Direct proteins to the nucleus

Answer

Direct proteins to the cytoplasm

Answer

Regulate gene expression

Answer

Facilitate DNA replication

Question 21

What is the name of the process by which DNA is transcribed into RNA within the nucleus?

Accepted Answer

Transcription

Answer

Translation

Answer

Replication

Answer

Condensation

Question 22

Which nuclear component provides a structural framework for chromosome interactions during DNA replication?

Accepted Answer

Nuclear matrix

Answer

Chromatin

Answer

Nuclear envelope

Answer

Nucleolus

Question 23

Which of the following is NOT a function of the nuclear envelope?

Accepted Answer

Protein synthesis

Answer

Gene expression

Answer

DNA replication

Answer

Protection of genetic material

Question 24

What is the primary role of the nucleolus in the cell?

Accepted Answer

To produce ribosomes

Answer

To store genetic material

Answer

To regulate gene expression

Answer

To facilitate DNA replication

Question 25

How does the nuclear envelope regulate the movement of molecules into and out of the nucleus?

Accepted Answer

Through nuclear pores

Answer

Through passive diffusion

Answer

Through facilitated diffusion

Answer

Through active transport

Question 26

During which process does the nuclear envelope undergo disassembly and reassembly?

Accepted Answer

Cell division

Answer

Gene expression

Answer

DNA replication

Answer

Protein synthesis

Question 27

Which of the following is NOT a primary function of the nuclear envelope?

Accepted Answer

Synthesizing ribosomes, which are essential for protein synthesis

Answer

Regulating the movement of materials between the nucleus and cytoplasm

Answer

Providing structural support to the nucleus and maintaining its shape

Answer

Housing nuclear pores for the selective transport of molecules

Question 28

The structure within the nucleus that is responsible for producing ribosomes, the cellular structures responsible for protein synthesis, is the:

Accepted Answer

Nucleolus

Answer

Nucleoplasm

Answer

Chromatin

Answer

Nuclear lamina

Question 29

The nuclear envelope, which surrounds the nucleus, consists of two:

Accepted Answer

Both B and C

Answer

Continuous membranes with no intervening space

Answer

Membranes separated by a narrow perinuclear space

Answer

Membranes perforated by numerous nuclear pores

Question 30

Which of the following proteins is a major component of the nuclear lamina, providing structural support to the nucleus?

Accepted Answer

Lamin A

Answer

Histone H1

Answer

Nucleolin

Answer

RNA polymerase II

Question 31

The process of gene expression, which allows cells to produce proteins, begins with:

Accepted Answer

Transcription within the nucleus

Answer

Translation in the cytoplasm

Answer

DNA replication in the nucleus

Answer

Protein synthesis in the ribosomes

Question 32

Which organelle is responsible for the production of ribosomes?

Accepted Answer

Nucleolus

Answer

Endoplasmic reticulum

Answer

Golgi apparatus

Answer

Mitochondria

Question 33

What is the primary function of the nuclear matrix?

Accepted Answer

Provides structural support and organization to the nucleus

Answer

Contains genetic material

Answer

Regulates gene expression

Answer

Synthesizes proteins

Question 34

What is the function of the nuclear lamina?

Accepted Answer

Provides structural support and maintains the shape of the nucleus

Answer

Synthesizes nuclear proteins

Answer

Contains the genetic material

Answer

Regulates the entry and exit of molecules

Question 35

Which of the following is NOT a component of the nuclear envelope?

Accepted Answer

Mitochondrial membrane

Answer

Endoplasmic reticulum

Answer

Nuclear lamina

Answer

Nuclear pores

Question 36

Which of the following is the site of DNA replication?

Accepted Answer

Nucleus

Answer

Mitochondria

Answer

Golgi apparatus

Answer

Cytoplasm

Question 37

What is the difference between euchromatin and heterochromatin?

Accepted Answer

Euchromatin is loosely packed and actively transcribed, while heterochromatin is tightly packed and mostly inactive

Answer

Euchromatin primarily contains DNA, while heterochromatin contains RNA

Answer

Euchromatin is located in the nucleus, while heterochromatin is found in the mitochondria

Question 38

Which of the following disorders results from defects in the nuclear lamina?

Accepted Answer

Laminopathies

Answer

Neurodegenerative disorders

Answer

Lysosomal storage diseases

Answer

Mitochondrial myopathies

Question 39

During cell division, what is the role of the nuclear envelope?

Accepted Answer

Disassembles to facilitate the separation of chromosomes

Answer

Synthesizes membranes for the newly formed nuclei

Answer

Regulates the movement of proteins into and out of the nucleus

Answer

Remains intact to prevent the loss of genetic material

Question 40

Which structure within the nucleus is responsible for ribosome synthesis?

Accepted Answer

Nucleolus

Answer

Nuclear pores

Answer

Chromosomes

Answer

Nuclear matrix

Question 41

The nuclear matrix provides structural support for the nucleus and plays a role in:

Accepted Answer

DNA replication and repair

Answer

Carbohydrate storage

Answer

Lipid metabolism

Answer

Protein synthesis

Question 42

Which of the following is a key difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have a nuclear envelope, while prokaryotic cells do not

Answer

Eukaryotic cells have more ribosomes than prokaryotic cells

Answer

Eukaryotic cells are larger than prokaryotic cells

Question 43

The nuclear pores are selectively permeable, allowing the passage of:

Accepted Answer

mRNA, tRNA, and proteins

Answer

Water, oxygen, and carbon dioxide

Answer

Only small molecules and ions

Answer

Lipids, carbohydrates, and ions

Question 44

Which of the following proteins is a major component of the nuclear lamina?

Accepted Answer

Laminin

Answer

Keratin

Answer

Collagen

Answer

Myosin

Question 45

The process of nuclear envelope breakdown occurs during:

Accepted Answer

Mitosis

Answer

Meiosis

Answer

Cytokinesis

Answer

Interphase

Question 46

Which of the following is a consequence of nuclear envelope breakdown?

Accepted Answer

Mixing of nuclear and cytoplasmic contents

Answer

Arrest of cell division

Answer

Formation of a new nuclear membrane

Answer

Inhibition of DNA replication

Question 47

The nuclear lamina plays a role in maintaining:

Accepted Answer

Nuclear shape and organization

Answer

Cell motility

Answer

Cellular respiration

Answer

Protein synthesis

Question 48

Which of the following factors regulates the movement of molecules through nuclear pores?

Accepted Answer

Nucleocytoplasmic transport receptors

Answer

Cytoplasmic viscosity

Answer

pH gradient

Answer

Membrane permeability