Important Questions Class 11 Biology Chapter 8: Cell The Unit Of Life With Answers

A cell is the basic structural and functional unit of all living organisms. Unicellular organisms perform all life functions inside one cell, while multicellular organisms divide work among many cells.

Every living organism begins with cellular organisation. A bacterium, an onion peel cell, a nerve cell, and a human cheek cell look different, but each follows the same basic rule of life. Important Questions Class 11 Biology Chapter 8 focus on cell theory, prokaryotic cells, eukaryotic cells, plasma membrane, cell wall, organelles, nucleus, and chromosome structure. CBSE 2026 questions often test definitions, comparisons, organelle functions, and NCERT exercise-based answers.

Key Takeaways

• Cell Theory: All living organisms are made of cells and products of cells.
• Virchow’s Principle: New cells arise only from pre-existing cells.
• 70S Ribosomes: Prokaryotic ribosomes contain 50S and 30S subunits.
• 80S Ribosomes: Eukaryotic cytoplasmic ribosomes contain 60S and 40S subunits.

Important Questions Class 11 Biology Chapter 8 Structure 2026

Important Questions Class 11 Biology Chapter 8: Key Concepts

These class 11 biology chapter 8 important questions cover the foundation of Cell: The Unit of Life. Students should learn definitions first, then compare structures.

Q1. What Is A Cell?

A cell is the fundamental structural and functional unit of all living organisms.

1. Structural Meaning:
   Every living organism is made of one or more cells.
2. Functional Meaning:
   A cell performs essential life activities.
3. Final Result:
   A complete cell is required for independent living

Q2. Why Is Cell Called The Basic Unit Of Life?

Cell is called the basic unit of life because it performs all essential life functions.

1. In Unicellular Organisms:
   One cell performs nutrition, respiration, excretion, and reproduction.
2. In Multicellular Organisms:
   Many cells divide work among tissues and organs.
3. Final Result:
   Life activities depend on cellular organisation

Q3. Who First Saw And Described A Live Cell?

Antonie Von Leeuwenhoek first saw and described a live cell.

1. Contribution:
   He observed living cells using a microscope.
2. Later Discovery:
   Robert Brown discovered the nucleus.
3. Final Result:
   Leeuwenhoek described live cells, and Brown discovered the nucleus

Q4. What Are Unicellular And Multicellular Organisms?

Unicellular organisms have one cell, while multicellular organisms have many cells.

1. Unicellular Organisms:
   A single cell performs all life functions.
2. Multicellular Organisms:
   Different cells perform specialised functions.
3. Final Result:
   Cell number separates unicellular and multicellular organisms

Q5. How Do Cells Differ In Shape And Size?

Cells differ in shape and size according to their functions.

1. Smallest Cells:
   Mycoplasmas are about 0.3 micrometre long.
2. Largest Isolated Cell:
   Ostrich egg is the largest isolated single cell.
3. Long Cells:
   Nerve cells are among the longest cells.
4. Final Result:
   Cell shape usually matches cell function

Cell The Unit Of Life Class 11 MCQ With Answers

These cell the unit of life class 11 important questions help students revise NCERT facts quickly. MCQs usually test names, functions, and structural differences.

Q1. Which Statement Is Not Correct?

“Robert Brown discovered the cell” is not correct.

1. Options:
   (A) Robert Brown discovered the cell
   (B) Schleiden and Schwann formulated cell theory
   (C) Virchow explained that cells arise from pre-existing cells
   (D) A unicellular organism performs life activities within one cell
2. Explanation:
   Robert Brown discovered the nucleus, not the cell.
3. Final Result:
   Answer: (A) Robert Brown discovered the cell

Q2. New Cells Generate From Which Source?

New cells generate from pre-existing cells.

1. Options:
   (A) Bacterial fermentation
   (B) Regeneration of old cells
   (C) Pre-existing cells
   (D) Abiotic materials
2. Explanation:
   Virchow stated “Omnis cellula-e cellula”.
3. Final Result:
   Answer: (C) Pre-existing cells

Q3. Which Cell Organelle Has Cristae?

Mitochondria have cristae.

1. Cristae Meaning:
   Cristae are infoldings of the inner mitochondrial membrane.
2. Function:
   They increase surface area for respiration.
3. Final Result:
   Answer: Mitochondria

Q4. Cisternae Are Found In Which Organelle?

Cisternae are flat disc-shaped sacs in the Golgi apparatus.

1. Structure:
   They are stacked parallel to one another.
2. Function:
   They help package and modify cell products.
3. Final Result:
   Answer: Golgi apparatus

Q5. Thylakoids Are Found In Which Organelle?

Thylakoids are flattened membranous sacs in chloroplasts.

1. Location:
   They are present in the stroma.
2. Arrangement:
   Stacked thylakoids form grana.
3. Final Result:
   Answer: Chloroplast

Q6. Which Statement About Prokaryotes Is Correct?

Prokaryotes do not have membrane-bound organelles.

1. Nucleus:
   They lack a well-defined nucleus.
2. Organelles:
   They lack mitochondria, Golgi complex, and ER.
3. Final Result:
   Answer: In prokaryotes, there are no membrane-bound organelles

Q7. Which Ribosomes Are Found In Prokaryotes?

Prokaryotes have 70S ribosomes.

1. Subunits:
   70S ribosomes contain 50S and 30S subunits.
2. Function:
   They help in protein synthesis.
3. Final Result:
   Answer: 70S ribosomes

Q8. Which Ribosomes Are Found In Eukaryotic Cytoplasm?

Eukaryotic cytoplasm contains 80S ribosomes.

1. Subunits:
   80S ribosomes contain 60S and 40S subunits.
2. Exception:
   Mitochondria and chloroplasts contain 70S ribosomes.
3. Final Result:
   Answer: 80S ribosomes

Q9. Which Model Explains Plasma Membrane Structure?

The fluid mosaic model explains plasma membrane structure.

1. Proposed By:
   Singer and Nicolson in 1972.
2. Main Idea:
   Proteins can move laterally in the lipid bilayer.
3. Final Result:
   Answer: Fluid mosaic model

Q10. Which Organelle Is Called The Powerhouse Of The Cell?

Mitochondria are called the powerhouse of the cell.

1. Reason:
   They produce ATP during aerobic respiration.
2. Structure:
   They have double membranes and cristae.
3. Final Result:
   Answer: Mitochondria

Cell Theory Class 11 Biology Important Questions

Cell theory class 11 biology questions are repeatedly asked because they connect discovery, structure, and origin of cells. Write the scientist’s name with the exact contribution.

Q1. State The Cell Theory.

Cell theory states that all living organisms are composed of cells and products of cells.

1. First Statement:
   All living organisms are made of cells and cell products.
2. Second Statement:
   All cells arise from pre-existing cells.
3. Final Result:
   Cell theory explains cellular organisation and cell origin

Q2. Who Formulated The Cell Theory?

Matthias Schleiden and Theodore Schwann formulated the cell theory.

1. Schleiden’s Work:
   He studied plant tissues and observed cells.
2. Schwann’s Work:
   He studied animal cells and identified plasma membrane.
3. Final Result:
   Schleiden and Schwann proposed the basic cell theory

Q3. How Did Virchow Modify Cell Theory?

Virchow modified cell theory by stating that new cells arise from pre-existing cells.

1. Latin Statement:
   Omnis cellula-e cellula.
2. Meaning:
   Every cell comes from a pre-existing cell.
3. Final Result:
   Virchow completed the modern cell theory

Q4. What Did Schwann Conclude About Plant And Animal Cells?

Schwann concluded that animals and plants are composed of cells and cell products.

1. Animal Cells:
   He observed a thin outer layer called plasma membrane.
2. Plant Cells:
   He identified cell wall as a unique plant cell feature.
3. Final Result:
   Schwann linked both plant and animal bodies to cells

Q5. Why Did The Original Cell Theory Need Modification?

The original cell theory did not explain how new cells were formed.

1. Missing Point:
   It explained composition, not cell origin.
2. Virchow’s Addition:
   Cells arise from pre-existing cells.
3. Final Result:
   Virchow gave cell theory its final form

Prokaryotic Cell Class 11 Important Questions

Prokaryotic cell class 11 questions focus on bacteria, blue-green algae, mycoplasma, PPLO, mesosome, plasmids, and ribosomes. These cells lack a membrane-bound nucleus.

Q1. What Are Prokaryotic Cells?

Prokaryotic cells are cells without a membrane-bound nucleus.

1. Examples:
   Bacteria, blue-green algae, mycoplasma, and PPLO.
2. Genetic Material:
   DNA is naked and not enclosed by a nuclear membrane.
3. Final Result:
   Prokaryotes lack a true nucleus and membrane-bound organelles

Q2. What Are The Main Characteristics Of Prokaryotic Cells?

Prokaryotic cells are small, rapidly dividing cells with naked DNA and 70S ribosomes.

1. Cell Wall:
   Most prokaryotes have a cell wall, except mycoplasma.
2. Nucleus:
   A well-defined nucleus is absent.
3. Organelles:
   Membrane-bound organelles are absent.
4. Ribosomes:
   70S ribosomes are present.
5. Final Result:
   Prokaryotic cells have simple organisation

Q3. What Are The Four Basic Shapes Of Bacteria?

The four basic bacterial shapes are bacillus, coccus, vibrio, and spirillum.

1. Bacillus:
   Rod-shaped bacteria.
2. Coccus:
   Spherical bacteria.
3. Vibrio:
   Comma-shaped bacteria.
4. Spirillum:
   Spiral-shaped bacteria.
5. Final Result:
   Bacterial shape helps in identification

Q4. What Is A Plasmid?

A plasmid is a small circular DNA molecule outside genomic DNA in many bacteria.

1. Function:
   It gives unique characters to bacteria.
2. Example:
   It may provide antibiotic resistance.
3. Biotechnology Use:
   It helps monitor bacterial transformation.
4. Final Result:
   Plasmids are extra-chromosomal bacterial DNA

Q5. What Is Mesosome Class 11 Biology?

Mesosome is an infolding of the plasma membrane in prokaryotic cells.

1. Structure:
   It may form vesicles, tubules, and lamellae.
2. Cell Wall Role:
   It helps in cell wall formation.
3. DNA Role:
   It helps in DNA replication and distribution.
4. Respiration Role:
   It increases membrane surface area and enzymatic content.
5. Final Result:
   Mesosome is a specialised plasma membrane extension

Q6. What Is The Cell Envelope In Bacteria?

The bacterial cell envelope is a three-layered protective covering.

1. Outermost Layer:
   Glycocalyx.
2. Middle Layer:
   Cell wall.
3. Inner Layer:
   Plasma membrane.
4. Final Result:
   Cell envelope protects and supports bacterial cells

Q7. What Is The Difference Between Slime Layer And Capsule?

Slime layer is loose, while capsule is thick and tough.

1. Slime Layer:
   It is a loose glycocalyx covering.
2. Capsule:
   It is a thick and tough glycocalyx covering.
3. Final Result:
   Both are forms of glycocalyx

Q8. What Are Pili And Fimbriae?

Pili and fimbriae are bacterial surface structures that do not help in motility.

1. Pili:
   Elongated tubular structures made of special protein.
2. Fimbriae:
   Small bristle-like fibres on the cell surface.
3. Function:
   Some fimbriae help bacteria attach to rocks or host tissues.
4. Final Result:
   Pili and fimbriae mainly help attachment

Q9. What Are Inclusion Bodies In Prokaryotes?

Inclusion bodies are reserve materials stored freely in the cytoplasm.

1. Membrane:
   They are not membrane-bound.
2. Examples:
   Phosphate granules, cyanophycean granules, and glycogen granules.
3. Gas Vacuoles:
   Present in blue-green and photosynthetic bacteria.
4. Final Result:
   Inclusion bodies store reserve materials

Q10. What Are Polyribosomes?

Polyribosomes are chains of ribosomes attached to a single mRNA.

1. Formation:
   Several ribosomes attach to one mRNA.
2. Function:
   They translate mRNA into proteins.
3. Final Result:
   Polyribosomes increase protein synthesis efficiency

Eukaryotic Cell Class 11 Questions And Answers

Eukaryotic cell class 11 questions focus on membrane-bound nucleus, organelles, plant cells, animal cells, and cytoplasmic compartmentalisation. These answers are useful for comparison questions.

Q1. What Are Eukaryotic Cells?

Eukaryotic cells are cells with a membrane-bound nucleus and membrane-bound organelles.

1. Examples:
   Protists, plants, animals, and fungi.
2. Nucleus:
   Nuclear envelope surrounds genetic material.
3. Organelles:
   Mitochondria, ER, Golgi complex, lysosomes, and vacuoles occur.
4. Final Result:
   Eukaryotic cells show compartmentalised organisation

Q2. How Are Prokaryotic And Eukaryotic Cells Different?

Prokaryotic cells lack a true nucleus, while eukaryotic cells have a true nucleus.

1. Prokaryotic Cells:
   Naked DNA and no membrane-bound organelles.
2. Eukaryotic Cells:
   Nuclear envelope and membrane-bound organelles.
3. Ribosomes:
   Prokaryotes have 70S ribosomes, while eukaryotic cytoplasm has 80S ribosomes.
4. Final Result:
   Nucleus and organelles separate the two cell types

Q3. How Are Plant And Animal Cells Different?

Plant cells have cell wall, plastids, and large vacuole, while animal cells have centrioles.

1. Plant Cells:
   Cell wall, plastids, and large central vacuole occur.
2. Animal Cells:
   Centrioles are usually present.
3. Shared Features:
   Both have plasma membrane, cytoplasm, nucleus, mitochondria, and ribosomes.
4. Final Result:
   Plant and animal cells differ in wall, plastids, vacuole, and centrioles

Q4. What Is Division Of Labour In Multicellular Organisms?

Division of labour means different cells perform different functions in multicellular organisms.

1. Example:
   RBCs transport gases.
2. Example:
   Nerve cells transmit impulses.
3. Example:
   Epithelial cells protect surfaces.
4. Final Result:
   Specialised cells improve body function

Q5. Why Are Eukaryotic Cells More Complex Than Prokaryotic Cells?

Eukaryotic cells are more complex because they have membrane-bound compartments.

1. Nucleus:
   It controls genetic activities.
2. Organelles:
   Each organelle performs a specific function.
3. Cytoskeleton:
   It supports shape, movement, and organisation.
4. Final Result:
   Compartmentalisation increases cellular efficiency

Cell Organelles Class 11 Important Questions

Cell organelles class 11 questions are common in short answer and diagram-based formats. Students should remember structure, membrane type, and function.

Q1. What Is Plasma Membrane Class 11 Biology?

Plasma membrane is a selectively permeable boundary around the cell.

1. Composition:
   It contains lipids, proteins, and carbohydrates.
2. Lipid Arrangement:
   Phospholipids form a bilayer.
3. Function:
   It controls movement of molecules.
4. Final Result:
   Plasma membrane regulates transport

Q2. Explain The Fluid Mosaic Model Class 11.

Fluid mosaic model states that proteins can move within a quasi-fluid lipid bilayer.

1. Proposed By:
   Singer and Nicolson in 1972.
2. Fluidity:
   Lipids allow lateral movement of proteins.
3. Importance:
   It helps in cell growth, secretion, endocytosis, and cell division.
4. Final Result:
   Fluid mosaic model explains membrane flexibility

Q3. What Is Passive Transport?

Passive transport is movement of molecules without energy use.

1. Direction:
   Molecules move from higher concentration to lower concentration.
2. Example:
   Neutral solutes move by simple diffusion.
3. Water Movement:
   Osmosis is diffusion of water.
4. Final Result:
   Passive transport follows the concentration gradient

Q4. What Is Active Transport?

Active transport is movement of molecules against the concentration gradient using ATP.

1. Direction:
   Molecules move from lower concentration to higher concentration.
2. Energy Source:
   ATP is used.
3. Example:
   Sodium-potassium pump.
4. Final Result:
   Active transport requires energy

Q5. What Is Cell Wall Class 11 Biology?

Cell wall is a rigid non-living outer covering outside the plasma membrane.

1. Present In:
   Plants and fungi.
2. Plant Cell Wall:
   Made mainly of cellulose, hemicellulose, pectins, and proteins.
3. Function:
   Gives shape, protection, and mechanical support.
4. Final Result:
   Cell wall protects plant cells

Q6. What Is Middle Lamella?

Middle lamella is a calcium pectate layer that holds neighbouring plant cells together.

1. Position:
   It lies between adjacent cell walls.
2. Function:
   It glues cells together.
3. Final Result:
   Middle lamella supports cell adhesion

Q7. What Is Endomembrane System Class 11?

Endomembrane system includes organelles whose functions are coordinated.

1. Included Organelles:
   ER, Golgi complex, lysosomes, and vacuoles.
2. Excluded Organelles:
   Mitochondria, chloroplasts, and peroxisomes.
3. Reason:
   Their functions are not coordinated with the endomembrane system.
4. Final Result:
   Endomembrane system coordinates internal transport and processing

Q8. What Is Rough Endoplasmic Reticulum?

Rough endoplasmic reticulum has ribosomes on its outer surface.

1. Main Function:
   It helps in protein synthesis and secretion.
2. Common Location:
   It is continuous with the outer nuclear membrane.
3. Final Result:
   RER works in protein-producing cells

Q9. What Is Smooth Endoplasmic Reticulum?

Smooth endoplasmic reticulum lacks ribosomes on its surface.

1. Main Function:
   It synthesises lipids.
2. Animal Cells:
   It synthesises steroidal hormones.
3. Final Result:
   SER is the main site of lipid synthesis

Q10. What Is Golgi Apparatus?

Golgi apparatus is a stack of flattened membrane-bound sacs called cisternae.

1. Cis Face:
   It receives material from ER.
2. Trans Face:
   It releases modified and packaged material.
3. Function:
   It forms glycoproteins and glycolipids.
4. Final Result:
   Golgi apparatus packages and modifies cell products

Q11. What Are Lysosomes?

Lysosomes are membrane-bound vesicles rich in hydrolytic enzymes.

1. Enzymes:
   They contain lipases, proteases, and carbohydrases.
2. Function:
   They digest proteins, lipids, carbohydrates, and nucleic acids.
3. Final Result:
   Lysosomes perform intracellular digestion

Q12. How Are Lysosomes And Vacuoles Different?

Lysosomes digest macromolecules, while vacuoles store water, sap, wastes, and other materials.

1. Lysosomes:
   They contain hydrolytic enzymes.
2. Vacuoles:
   They are storage spaces surrounded by tonoplast.
3. Final Result:
   Both are endomembrane structures with different functions

Q13. What Are Mitochondria And Chloroplast Class 11?

Mitochondria produce ATP, while chloroplasts trap light energy for photosynthesis.

1. Mitochondria:
   Sites of aerobic respiration.
2. Chloroplasts:
   Sites of photosynthesis in plant cells.
3. Shared Feature:
   Both are double membrane-bound and contain circular DNA.
4. Final Result:
   Both are semi-autonomous organelles

Q14. Why Are Mitochondria Called Powerhouses Of The Cell?

Mitochondria are called powerhouses because they produce ATP.

1. Process:
   Aerobic respiration occurs in mitochondria.
2. Structure:
   Cristae increase surface area for reactions.
3. Final Result:
   ATP is the cellular energy currency

Q15. What Are Plastids?

Plastids are pigment-containing organelles found in plant cells and euglenoids.

1. Chloroplasts:
   Contain chlorophyll and carotenoids.
2. Chromoplasts:
   Contain coloured carotenoid pigments.
3. Leucoplasts:
   Store nutrients like starch, oils, and proteins.
4. Final Result:
   Plastids help in photosynthesis, colour, and storage

Q16. What Are Ribosomes Class 11 Biology?

Ribosomes are non-membrane-bound organelles made of RNA and proteins.

1. Function:
   They are sites of protein synthesis.
2. Prokaryotic Ribosomes:
   70S ribosomes have 50S and 30S subunits.
3. Eukaryotic Cytoplasmic Ribosomes:
   80S ribosomes have 60S and 40S subunits.
4. Final Result:
   Ribosomes make proteins

Q17. What Is Cytoskeleton?

Cytoskeleton is a network of protein filaments in the cytoplasm.

1. Components:
   Microtubules, microfilaments, and intermediate filaments.
2. Functions:
   Mechanical support, motility, and cell shape maintenance.
3. Final Result:
   Cytoskeleton supports cell structure and movement

Q18. What Is The 9+2 Arrangement In Cilia And Flagella?

The 9+2 arrangement means nine peripheral microtubule doublets surround two central microtubules.

1. Core:
   The core is called axoneme.
2. Covering:
   Plasma membrane covers cilia and flagella.
3. Final Result:
   Eukaryotic cilia and flagella show 9+2 arrangement

Q19. What Are Centrosome And Centrioles?

Centrosome usually contains two perpendicular centrioles in animal cells.

1. Centriole Structure:
   Each centriole has nine peripheral triplet fibrils.
2. Function:
   Centrioles form basal bodies and spindle apparatus.
3. Final Result:
   Centrioles help in cell division and locomotory structures

Nucleus And Chromosomes Class 11 Biology Questions

Nucleus and chromosomes class 11 questions are important because the nucleus controls cell activities and heredity. Most answers should mention chromatin, nucleolus, nuclear envelope, and centromere.

Q1. What Is Nucleus?

Nucleus is a membrane-bound organelle that contains genetic material and controls cell activities.

1. Discovery:
   Robert Brown first described the nucleus.
2. Main Components:
   Nuclear envelope, nucleoplasm, nucleolus, and chromatin.
3. Final Result:
   Nucleus controls heredity and cellular functions

Q2. What Are Nuclear Pores?

Nuclear pores are openings in the nuclear envelope.

1. Formation:
   They form where the two nuclear membranes fuse.
2. Function:
   They allow movement of RNA and proteins.
3. Direction:
   Movement occurs between nucleus and cytoplasm.
4. Final Result:
   Nuclear pores regulate nuclear-cytoplasmic exchange

Q3. What Is Nucleolus?

Nucleolus is a non-membrane-bound spherical structure inside the nucleus.

1. Function:
   It is the site of active ribosomal RNA synthesis.
2. Active Cells:
   Cells making more proteins have larger or more nucleoli.
3. Final Result:
   Nucleolus helps form ribosomes

Q4. What Is Chromatin?

Chromatin is a network of nucleoprotein fibres inside the interphase nucleus.

1. Components:
   DNA, histone proteins, non-histone proteins, and RNA.
2. During Division:
   Chromatin condenses into chromosomes.
3. Final Result:
   Chromatin carries hereditary material

Q5. What Is Centromere?

Centromere is the primary constriction of a chromosome.

1. Function:
   It holds two chromatids together.
2. Kinetochore:
   Disc-shaped kinetochores occur on its sides.
3. Final Result:
   Centromere helps chromosome movement during division

Q6. How Does Centromere Position Classify Chromosomes?

Chromosomes are classified as metacentric, submetacentric, acrocentric, and telocentric by centromere position.

1. Metacentric:
   Centromere lies in the middle and forms two equal arms.
2. Submetacentric:
   Centromere lies slightly away from the middle.
3. Acrocentric:
   Centromere lies close to one end.
4. Telocentric:
   Centromere lies at the terminal end.
5. Final Result:
   Centromere position decides chromosome type

Cell The Unit Of Life NCERT Questions

These cell the unit of life NCERT questions are based on exercise patterns. Write answers in direct, structured form for CBSE 2026.

Q1. Match Cristae, Cisternae, And Thylakoids With Their Correct Structures.

Cristae are mitochondrial infoldings, cisternae are Golgi sacs, and thylakoids are chloroplast sacs.

1. Cristae:
   Infoldings in mitochondria.
2. Cisternae:
   Flat disc-shaped sacs in Golgi apparatus.
3. Thylakoids:
   Flat membranous sacs in chloroplast stroma.
4. Final Result:
   a-ii, b-iii, c-i

Q2. How Do Neutral Solutes Move Across Plasma Membrane?

Neutral solutes move across the plasma membrane by simple diffusion.

1. Direction:
   They move from higher concentration to lower concentration.
2. Energy:
   No ATP is required.
3. Final Result:
   Neutral solutes move by passive transport

Q3. Can Polar Molecules Move Across The Membrane In The Same Way?

Polar molecules cannot move through the nonpolar lipid bilayer by simple diffusion.

1. Problem:
   Lipid bilayer blocks many polar molecules.
2. Transport Method:
   Carrier proteins help their movement.
3. Final Result:
   Polar molecules need facilitated transport

Q4. Name Two Double Membrane-Bound Organelles.

Mitochondria and chloroplasts are double membrane-bound organelles.

1. Mitochondria:
   They produce ATP through aerobic respiration.
2. Chloroplasts:
   They trap light energy for photosynthesis.
3. Final Result:
   Both contain circular DNA and 70S ribosomes

Q5. What Are The Characteristics Of Prokaryotic Cells?

Prokaryotic cells lack a membrane-bound nucleus and membrane-bound organelles.

1. Genetic Material:
   Naked DNA lies in cytoplasm.
2. Ribosomes:
   70S ribosomes are present.
3. Cell Wall:
   Most have a cell wall, except mycoplasma.
4. Final Result:
   Prokaryotic cells have simple organisation

Q6. Cell Is The Basic Unit Of Life. Discuss In Brief.

Cell is the basic unit of life because it performs all living functions.

1. Structural Role:
   All organisms are made of cells.
2. Functional Role:
   Cells carry out metabolism, growth, and reproduction.
3. Origin Rule:
   New cells arise from pre-existing cells.
4. Final Result:
   Cell is the structural and functional unit of life

Q7. Both Lysosomes And Vacuoles Are Endomembrane Structures. How Do They Differ?

Lysosomes digest substances, while vacuoles store substances.

1. Lysosomes:
   They contain hydrolytic enzymes active at acidic pH.
2. Vacuoles:
   They contain water, sap, waste, and stored materials.
3. Final Result:
   Their structures are membrane-bound, but their functions differ

Q8. Describe The Structure Of Nucleus.

Nucleus contains nuclear envelope, nucleoplasm, chromatin, and nucleolus.

1. Nuclear Envelope:
   It has two membranes and nuclear pores.
2. Nucleoplasm:
   It contains chromatin and nucleolus.
3. Chromatin:
   It carries DNA and proteins.
4. Final Result:
   Nucleus controls heredity and cell activities

Q9. Describe The Structure Of Centrosome.

Centrosome contains two centrioles placed perpendicular to each other.

1. Centriole Pattern:
   Each centriole has nine peripheral triplet fibrils.
2. Central Region:
   A proteinaceous hub connects to triplets by radial spokes.
3. Function:
   It forms spindle fibres during animal cell division.
4. Final Result:
   Centrosome helps organise division structures

Q10. What Are Microbodies?

Microbodies are small membrane-bound vesicles containing enzymes.

1. Occurrence:
   They occur in plant and animal cells.
2. Function:
   They carry out enzyme-based cellular reactions.
3. Final Result:
   Microbodies are enzyme-containing vesicles