100+ MCQs on General Physiology – The Cell | Medical Students

Introduction to the Cell

The cell is the fundamental unit of life, forming the basic structural and functional component of all living organisms. Cells carry out essential physiological processes and are classified into prokaryotic (bacteria and archaea) and eukaryotic (plants, animals, fungi, and protists) types.

Cell Theory

Cell theory was developed by Schleiden, Schwann, and Virchow, and it states that:

All living organisms are composed of one or more cells.
The cell is the basic unit of life.
All cells arise from pre-existing cells.

Structure of a Eukaryotic Cell

A eukaryotic cell consists of three major components:

Cell Membrane (Plasma Membrane)
Cytoplasm and Organelles
Nucleus

1. Cell Membrane

Composition: Phospholipid bilayer with embedded proteins.
Functions:
- Maintains cell shape and integrity.
- Regulates transport of substances (selectively permeable).
- Facilitates cell signaling and communication.

2. Cytoplasm and Organelles

The cytoplasm contains various organelles that perform specialized functions:

Mitochondria – The powerhouse of the cell, responsible for ATP production.
Ribosomes – Protein synthesis sites, found freely in the cytoplasm or attached to the rough ER.
Endoplasmic Reticulum (ER):
- Rough ER (RER) – Protein synthesis and transport.
- Smooth ER (SER) – Lipid synthesis and detoxification.
Golgi Apparatus – Modifies, sorts, and packages proteins.
Lysosomes – Contain digestive enzymes for waste degradation.
Peroxisomes – Involved in lipid metabolism and detoxification.
Cytoskeleton – Provides structural support and aids in intracellular transport.

3. Nucleus

Structure: Surrounded by a nuclear envelope with nuclear pores.
Components:
- Nucleolus – Produces ribosomal RNA (rRNA).
- Chromatin – Contains DNA and associated proteins.
Function: Controls gene expression and replication.

Functions of the Cell

Cells perform various essential functions:

Metabolism – Chemical reactions for energy production.
Growth and Development – Increase in size and complexity.
Reproduction – Cell division through mitosis (somatic cells) and meiosis (gametes).
Homeostasis – Maintaining internal balance.
Transport Mechanisms:
- Passive Transport – Diffusion, facilitated diffusion, osmosis.
- Active Transport – Requires ATP (e.g., sodium-potassium pump).
Cell Communication – Through chemical signals and receptors.

Types of Cells in the Human Body

Epithelial Cells – Line organs and body surfaces.
Muscle Cells – Facilitate movement (skeletal, cardiac, smooth).
Nerve Cells (Neurons) – Conduct electrical impulses.
Connective Tissue Cells – Provide support (fibroblasts, adipocytes, osteocytes).
Blood Cells – RBCs (oxygen transport), WBCs (immune response), Platelets (clotting).

Cell Cycle and Division

Cells undergo division for growth and repair through:

Mitosis – Produces two identical daughter cells.
Meiosis – Produces gametes with half the chromosome number.

Here are 100+ Multiple Choice Questions (MCQs) related to General Physiology – The Cell

INTRODUCTION OF CELL

Who discovered the cell?
a) Robert Hooke
b) Rudolf Virchow
c) Antonie van Leeuwenhoek
d) Matthias Schleiden
Answer: a) Robert Hooke
What is the basic unit of life?
a) Tissue
b) Organ
c) Cell
d) Atom
Answer: c) Cell
Which of the following is a unicellular organism?
a) Human
b) Amoeba
c) Dog
d) Tree
Answer: b) Amoeba
What is the main function of a cell?
a) To produce energy
b) To carry out life processes
c) To store water
d) To regulate temperature
Answer: b) To carry out life processes
Which organelle is known as the powerhouse of the cell?
a) Ribosome
b) Mitochondria
c) Nucleus
d) Golgi apparatus
Answer: b) Mitochondria
The study of cells is known as?
a) Histology
b) Cytology
c) Physiology
d) Pathology
Answer: b) Cytology
Which of the following is absent in prokaryotic cells?
a) Cell membrane
b) Ribosome
c) Nucleus
d) Cytoplasm
Answer: c) Nucleus
What is the fluid inside the cell called?
a) Nucleoplasm
b) Cytoplasm
c) Protoplasm
d) Endoplasm
Answer: b) Cytoplasm
Who proposed the cell theory?
a) Schwann and Virchow
b) Schleiden and Schwann
c) Hooke and Leeuwenhoek
d) Mendel and Watson
Answer: b) Schleiden and Schwann
Which statement is NOT a part of the cell theory?
a) All living organisms are made up of cells
b) Cells arise from pre-existing cells
c) Cells contain genetic material
d) All cells contain chloroplasts
Answer: d) All cells contain chloroplasts
What is the main function of ribosomes?
a) Lipid synthesis
b) Protein synthesis
c) DNA replication
d) Energy production
Answer: b) Protein synthesis
What are the two main types of cells?
a) Prokaryotic and Eukaryotic
b) Plant and Animal
c) Bacterial and Viral
d) Fungal and Bacterial
Answer: a) Prokaryotic and Eukaryotic
Which cell organelle is responsible for photosynthesis?
a) Nucleus
b) Mitochondria
c) Chloroplast
d) Golgi Apparatus
Answer: c) Chloroplast
In which type of cell is a cell wall present?
a) Animal cell
b) Fungal cell
c) Human cell
d) Bacterial cell
Answer: d) Bacterial cell
What is the genetic material in a cell?
a) Carbohydrates
b) Proteins
c) DNA and RNA
d) Lipids
Answer: c) DNA and RNA
What is the function of lysosomes?
a) Digestion of waste materials
b) Energy production
c) Protein synthesis
d) Photosynthesis
Answer: a) Digestion of waste materials
The semi-permeable membrane of a cell is called?
a) Nucleus
b) Cytoplasm
c) Cell wall
d) Plasma membrane
Answer: d) Plasma membrane
Which cell organelle is called the "suicidal bag"?
a) Mitochondria
b) Lysosome
c) Ribosome
d) Golgi Apparatus
Answer: b) Lysosome
Which of the following structures is only found in plant cells?
a) Centrioles
b) Lysosomes
c) Chloroplast
d) Mitochondria
Answer: c) Chloroplast
What is the function of the Golgi apparatus?
a) Lipid synthesis
b) Protein modification and packaging
c) ATP production
d) DNA replication
Answer: b) Protein modification and packaging

STRUCTURE OF CELL

What is the function of the nucleus?
a) Energy production
b) DNA storage and gene regulation
c) Protein synthesis
d) Digestion
Answer: b) DNA storage and gene regulation
What is the role of the rough endoplasmic reticulum?
a) Protein synthesis
b) Lipid synthesis
c) Cell division
d) Energy production
Answer: a) Protein synthesis
Which of the following is a component of the cytoskeleton?
a) Microtubules
b) Ribosomes
c) Lysosomes
d) Nucleoplasm
Answer: a) Microtubules
Which organelle detoxifies drugs in the liver?
a) Mitochondria
b) Rough ER
c) Smooth ER
d) Lysosome
Answer: c) Smooth ER
What is the function of centrioles?
a) Photosynthesis
b) Cell division
c) Protein synthesis
d) Transport of substances
Answer: b) Cell division
What structure controls the movement of substances in and out of the cell?
a) Mitochondria
b) Nucleus
c) Cell membrane
d) Ribosome
Answer: c) Cell membrane
Which organelle is responsible for ATP production?
a) Golgi apparatus
b) Mitochondria
c) Endoplasmic reticulum
d) Ribosome
Answer: b) Mitochondria
What is the main function of peroxisomes?
a) Digestion
b) Energy production
c) Detoxification
d) DNA replication
Answer: c) Detoxification
Which of the following is NOT a function of the plasma membrane?
a) Protects the cell
b) Provides structural support
c) Generates energy
d) Controls substance movement
Answer: c) Generates energy
What is the shape of a red blood cell?
a) Cuboidal
b) Spherical
c) Biconcave
d) Cylindrical
Answer: c) Biconcave
What is the major function of the cytoskeleton?
a) Storage of nutrients
b) Cell shape and movement
c) Protein synthesis
d) Lipid metabolism
Answer: b) Cell shape and movement
The liquid portion of the nucleus is called?
a) Cytoplasm
b) Nucleoplasm
c) Protoplasm
d) Stroma
Answer: b) Nucleoplasm
What are the folds inside mitochondria called?
a) Cristae
b) Stroma
c) Matrix
d) Thylakoids
Answer: a) Cristae
What gives the rough endoplasmic reticulum its rough appearance?
a) Presence of ribosomes
b) Presence of lipids
c) Presence of enzymes
d) Presence of pores
Answer: a) Presence of ribosomes
Which cell organelle is responsible for modifying, sorting, and packaging proteins?
a) Ribosomes
b) Golgi Apparatus
c) Lysosomes
d) Mitochondria
Answer: b) Golgi Apparatus
What is the function of nuclear pores?
a) ATP synthesis
b) Transport of molecules
c) Protein synthesis
d) Lipid storage
Answer: b) Transport of molecules
Which cytoskeletal component is involved in chromosome movement during cell division?
a) Microtubules
b) Microfilaments
c) Intermediate filaments
d) Ribosomes
Answer: a) Microtubules
What is the major function of tight junctions in cells?
a) Cell movement
b) Cell communication
c) Prevent leakage
d) Protein transport
Answer: c) Prevent leakage
The major component of the plant cell wall is?
a) Cellulose
b) Chitin
c) Glycogen
d) Peptidoglycan
Answer: a) Cellulose
The plasma membrane is made up of?
a) Proteins and Carbohydrates
b) Phospholipids and Proteins
c) DNA and RNA
d) Nucleic acids and Lipids
Answer: b) Phospholipids and Proteins
Which organelle contains digestive enzymes?
a) Golgi Apparatus
b) Peroxisomes
c) Lysosomes
d) Mitochondria
Answer: c) Lysosomes
What is the function of microfilaments?
a) Storage of proteins
b) Cell movement and contraction
c) Protein synthesis
d) DNA replication
Answer: b) Cell movement and contraction
Which part of the cytoskeleton is involved in muscle contraction?
a) Microtubules
b) Microfilaments
c) Intermediate filaments
d) Centrioles
Answer: b) Microfilaments
Which of the following organelles has its own DNA?
a) Ribosome
b) Golgi apparatus
c) Mitochondria
d) Lysosome
Answer: c) Mitochondria
What is the primary function of clathrin-coated vesicles?
a) ATP production
b) Endocytosis
c) Protein synthesis
d) DNA replication
Answer: b) Endocytosis
What is the function of the centrosome?
a) ATP production
b) Cell division and organization of microtubules
c) Lipid metabolism
d) DNA replication
Answer: b) Cell division and organization of microtubules
Which organelle is responsible for making steroid hormones?
a) Rough ER
b) Smooth ER
c) Golgi Apparatus
d) Lysosomes
Answer: b) Smooth ER
What is the function of peroxisomes?
a) ATP production
b) Detoxification
c) Protein synthesis
d) DNA replication
Answer: b) Detoxification
What gives RBCs their unique biconcave shape?
a) Nucleus
b) Hemoglobin
c) Lack of a nucleus and cytoskeletal arrangement
d) Presence of lysosomes
Answer: c) Lack of a nucleus and cytoskeletal arrangement
Which of the following is NOT a characteristic of eukaryotic cells?
a) Nucleus present
b) Membrane-bound organelles
c) Small ribosomes (70S)
d) Large ribosomes (80S)
Answer: c) Small ribosomes (70S)
The function of histones in the nucleus is?
a) DNA replication
b) Packaging and regulation of DNA
c) Protein synthesis
d) Cell signaling
Answer: b) Packaging and regulation of DNA
Which of the following allows cell communication?
a) Lysosomes
b) Gap junctions
c) Peroxisomes
d) Microtubules
Answer: b) Gap junctions
Where is rRNA synthesized?
a) Mitochondria
b) Nucleolus
c) Ribosome
d) Golgi Apparatus
Answer: b) Nucleolus
Which part of the mitochondria contains enzymes for ATP synthesis?
a) Inner membrane
b) Outer membrane
c) Intermembrane space
d) Cristae
Answer: a) Inner membrane
The site of aerobic respiration in a cell is?
a) Golgi apparatus
b) Mitochondria
c) Cytoplasm
d) Ribosome
Answer: b) Mitochondria
Which organelle is abundant in white blood cells for digesting bacteria?
a) Lysosomes
b) Mitochondria
c) Peroxisomes
d) Golgi Apparatus
Answer: a) Lysosomes
The part of the nucleus that controls gene expression is?
a) Nucleoplasm
b) Chromatin
c) Nucleolus
d) Ribosomes
Answer: b) Chromatin
The function of the extracellular matrix is?
a) DNA storage
b) Cell adhesion and communication
c) Protein synthesis
d) ATP production
Answer: b) Cell adhesion and communication
What is the function of exocytosis?
a) Taking materials into the cell
b) Removing waste and secreting substances
c) Storing genetic material
d) Producing ATP
Answer: b) Removing waste and secreting substances
Which part of the cell cycle involves active division?
a) S phase
b) G1 phase
c) G2 phase
d) M phase
Answer: d) M phase

Conclusion

The cell is a highly organized structure responsible for all physiological functions of life. Understanding its structure and function is fundamental for medical and pharmacy students, as it lays the foundation for studying physiology, pathology, and pharmacology.

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