Courses for Kids
Free study material
Offline Centres
Store Icon
NEET 2022 | Class 12

NEET Important Chapter: Cell - The Unit of Life

Get plus subscription and access unlimited live and recorded courses
Cell - The Unit of Life

Cell - The Unit of Life

Last updated date: 18th Jul 2024
Total views: 240.6k
Views today: 3.35k

Cell - The Unit of Life is a very important part of the NEET syllabus and this article will help you to get the insights and also one can refer to this for last-minute revision purposes. This chapter is an important component in Unit Structure and Function because it is the source of 2-3 questions per year. The chapter is entirely theoretical and requires thorough revision.

So, in this article, you’ll be studying about the cell, its discovery, the scientists involved, the kinds of cell, cell membrane, cell wall, and other major components of the cell. This synopsis of the chapter would be highly helpful to the student in order to gain the maximum marks. 

Important topics of Cell - The Unit of Life 

  • Cell theory 

  • Kinds of cell

  • Cell Organelles

  • Nucleus- Chromosomes

  • Mitochondria

  • Golgi Apparatus

Important Concepts of the Chapter


  • A cell is known to be the most basic functional and structural unit of life. 

  • Anton van Leeuwenhoek was the first person to see a cell and characterise it as a living organism. 

  • A cell is considered a structure comprising organelles that perform essential processes in order for the cell to survive. Not all cells, however, are just the same.

Plants and animals have cells that are substantially different. The lack of cell walls in animal cells is among the most significant differences that exist. The egg or female ovum is the largest cell in the human body and is around 1 mm across. However, the granule cell, which is present in the human cerebellum and measures around 4.5 micrometres in diameter, is the smallest cell.

Cell Theory

  • This scientific hypothesis stated that all living entities are made up of cells and that new cells are generated from pre-existing cells. 

  • It was first postulated by Matthias Schleiden and Theodor Schwann. 

  • Despite the fact that Schleiden and Schwann proposed the hypothesis, numerous renowned scientists have added to it, elevating it from a theory to a commonly acknowledged fact.

Types of Cells

Prokaryotic cells and Eukaryotic cells are the two different types of cells.

  1. Prokaryotic Cells: Prokaryotic cells are unicellular microbes that are among the oldest living things on the planet. Because a typical prokaryotic cell is made up of only one membrane, all reactions take place in the cytoplasm. They can live on their own or in the guts of other animals, such as ruminants (cows and buffaloes).

  2. Eukaryotic Cells: Eukaryotic cells, unlike prokaryotic cells, have a nucleus that is encased inside a membrane. Eukaryotic organisms are multicellular organisms that belong to the Eukaryota domain.

Prokaryotic and Eukaryotic Cells

At the bottom of the article, students can find the difference and similarities between the two kinds of cells.

Cell Structure

  • Cell Membrane: A structure which provides rigidity and protection to the cell and controls the movement of biomolecules in and out of the cell. Made up of phospholipid layers.

  • Cell wall: It is the outermost layer found only in plant cells and is made up of cellulose, hemicellulose, and pectin. It provides stiffness and protects the plant cell from mechanical shocks and injuries.

  • Cytoplasm: It is a jelly-like pool inside the cell membrane, carries cell organelles, and is the site for Biochemical reactions like glycolysis.

Cell Organelles

  1. Nucleus

  • It is the main component of a cell, carries DNA, and is responsible for growth and development.

  1. Nucleolus

  • Present inside the nucleus, site for ribosome synthesis, and also controls cellular reproduction.

  1. Nuclear Membrane

  • It is a membrane-enclosed nucleus and thus forms a barrier between the genetic material and other cell components.

  1. Chromosomes

  • Condensed chromatin fibre causes the formation of chromosomes. Chromosomes contain DNA and histones and determine the sex of an individual. 

  • Humans carry 23 pairs of chromosomes. Two sister chromatids are attached by a structure called a centromere.

  1. Centrosome

  • Two cylindrical structures that take place in cell division.

  1. Mitochondria

  • This is a double-layered structure commonly called the powerhouse of the cell and synthesises ATP during cellular respiration. 

  • Mitochondria carries cristae which are formed by the inward foldings of the inner membrane. 

  • The mitochondrial matrix also contains DNA, along with RNA, ribosomes, and proteins.

  1. Endoplasmic Reticulum

  • Tubular structures seen in the proximity of the nucleus. Two types of ER are found in the cell - rough and smooth endoplasmic reticulum.

  • RER is called so because of the presence of ribosomes on its surface. These structures are associated with protein synthesis.

  • SER does not have ribosomes on its surface and is involved with lipid synthesis.

  1. Ribosome

  • Ribosomes are present on the surface of the endoplasmic reticulum and are called the protein factory of the cell. 

  • Polyribosomes are formed when ribosomes get attached to mRNA.

  1. Golgi Bodies

  • These structures are responsible for the transportation of materials within the cytoplasm and carry Cisternae, which is the site for the modification and synthesis of various biomolecules. 

  • Its functions include assorting the proteins (glycoproteins) and lipids (glycolipids) for secretion.

  1. Lysosome

  • Lysosome is also called as cell’s suicide bags, engulfs foreign particles and other metabolic wastes, helps in renewing the cells, and contains enzymatic secretions that break down organic matter.

  1. Chloroplasts

  • Double-layered structure found only in plants. 

  • The structure bound by the inner membrane is called the stroma. 

  • The stroma contains thylakoids; stacks of thylakoids grouped together are known as grana. 

  • Chloroplasts contain chlorophyll and are the site for photosynthesis.

  1. Vacuoles

  • Centre for the storage of food, water, and other organic material.

  1. Plastids

  • Collective term given to chloroplast, chromoplast, and leucoplast and responsible for photosynthesis and the production and storage of metabolites. 

Differences Between Prokaryotic and Eukaryotic Cell

Prokaryotic Cell

Eukaryotic Cell



Unicellular and multicellular

Membrane-bound organelles



Cell size

Smaller size ranging between 0.1 and 5 m.

Larger size ranging between 10 and 100 m.

Cell wall

Chemically complex cell wall is observed.

Chemically simple cell wall is observed.




DNA form




Smaller and spherical kind

Larger and linear kind


Seen with cell organelles

Seen without cell organelles





Small Ribosomes (70S, having subunits 50S and 30S)

Large Ribosomes (80S,  having subunits - 60S and 40S)

Endoplasmic Reticulum

Not seen



Centrosomes and lysosomes, both are absent.

Centrosomes and lysosomes, both are present.



Barely found


Small sized

Large sized

Cell division

Happens via binary fission

Happens via mitosis



Sexual and Asexual


Archaea and Bacteria

Animal and Plant cell

Similarities Between Prokaryotic Cell and Eukaryotic Cell

  • Ribosomes are found in both cells and play a role in protein synthesis.

  • DNA that is linked to genes can be found in both types of cells.

  • In both, the cell wall is present.

  • There are four sorts of main molecules that are found in both of them.

  • In both cases, the process of DNA copying is comparable.

  • Both share a few significant metabolic pathways.

  • In both, the photosynthesis process is comparable.

  • There are twenty standard amino acids in both cells.

  • Both have the same genetic code.

  • ATP is the energy source in both cells.

Solved Examples From the Chapter 

1. The cell wall of algae is made up of which substance?

(a) Protein

(b) Mannans

(c) Lipid

(d) all of the above

Ans: (b) Mannans

2. Match the Following:

Column I

Column II

(a) Cristae

(i) Flat membranous sacs in stroma

(b) Cisternae

(ii) Infoldings in mitochondria

(c) Thylakoids

(iii) Disc-shaped sacs in Golgi apparatus


Column I

Column II

(a) Cristae

(ii) Infoldings in mitochondria

(b) Cisternae

(iii) Disc-shaped sacs in Golgi apparatus

(c) Thylakoids

(i) Flat membranous sacs in stroma

Cristae: The inner membrane of mitochondria folds inward to form cristae, a finger-like projection. It expands the absorption surface area.

Cisternae: A space between the membranes of flattened sacs of the Golgi apparatus and the endoplasmic reticulum, as well as between the two membranes of the nuclear envelope that contains fluid.

Thylakoids: Thylakoids are disc-shaped structures that are stacked to form grana. These include photosynthetic pigments and serve as a location for photosynthesis light reactions.

3. Name two cell organelles that are double membrane bound. 

Ans: Mitochondria and chloroplasts are the two organelles that are double-membrane bound.

4. Which of the following is not correct?

(a) Robert Brown discovered the cell.

(b) Schleiden and Schwann formulated the cell theory.

(c) Virchow explained that cells are formed from pre-existing cells.

(d) A unicellular organism carries out its life activities within a single cell.

Ans: Robert Brown discovered the cell. - It is a false statement.

The first person to see a cell was Robert Hook. He used a very primitive microscope and observed empty blocks like structure in the cork cells which were named as cells.

Solved Problems of Previous Year Question From the Chapter

1. When the Centromere is situated in the middle of two equal arms of chromosomes, the chromosome is referred to as:

  1. Acrocentric

  2. Sub-metacentric

  3. Telocentric

  4. Meta-centric

Ans: d. Meta-centric.

The chromosome is called Metacentric when the centromere lies in the centre of two equal arms of chromosomes.

Sub-metacentric chromosomes have the centromere located somewhat distant from the middle of the chromosome.

Acrocentric chromosomes are those in which the centromere is located relatively close to one end of the chromosome.

When the centromere is located at the end of the chromosome, it is referred to as telocentric.

2. The size of Pleuropneumonia-like Organism (PPLO) is:

  1. 0.2 μm

  2. 1-2 μm

  3. 10-20 μm

  4. 0.1 μm

Ans: d. 0.1 μm.

Key point to remember: With a diameter of 0.1 micrometres, PPLO is also known as mycoplasma. It's the tiniest cell ever found. 

3. The Golgi complex participates in

  1. Activation of amino acid

  2. Fatty acid breakdown

  3. Respiration in Bacteria

  4. Formation of secretory vesicles

Ans: d. Formation of Secretory Vesicles.

The Golgi complex is a membrane-bound organelle found solely in eukaryotic cells. It has a role in secretory vesicle production. 

Key Point to Remember: In bacteria, mesosomes perform respiration, ribosomes do amino acid activation as part of protein synthesis, and mitochondria perform fatty acid degradation via beta-oxidation.

4. The shorter and longer arms of submetacentric chromosomes are referred to as:

  1. S-arm and l-arm, respectively.

  2. q-arm and p-arm, respectively.

  3. m-arm and n-arm, respectively.

  4. p-arm and q-arm, respectively.

Ans: d. p-arm and q- arm, respectively.

Sub metacentric chromosome is Heterobrachial.

The small arm is referred to as the 'p' arm (p stands for petite/short) while the long arm is referred to as the 'q' arm.

Key Point to Remember: Human chromosomes have 2 arms - the p (short) arm and the q (long) arm, and both are separated by the centromere.  

Practice Questions

1. Which of the following is not true of a eukaryotic cell?

  1. Cell wall is made up of peptidoglycans.

  2. Mitochondria contain circular DNA.

  3. It has 80S type of ribosome present in the cytoplasm.

  4. Membrane-bound organelles are present.

Ans: a. Cell wall is made up of peptidoglycans.

Option a is incorrect as the cell wall is made up of cellulose in eukaryotic cells. The other options are true for eukaryotes, that is, mitochondria do carry circular DNA, the organelles present are membrane bound, which includes Golgi apparatus, chloroplasts etc., and the type of ribosome present in the cytoplasm is 80S. 

Point to Remember: The cell wall of prokaryotic cells is made up of peptidoglycan. 

2. The organelle common among prokaryotic and eukaryotic cells is 

  1. Centrosome

  2. Peroxisome

  3. Ribosome

  4. Glyoxysome

Ans: c. Ribosome.

There exist two different kinds of cells, namely, prokaryotes and eukaryotes.

The nucleus, endoplasmic reticulum, and mitochondria are membrane-bound organelles in eukaryotic cells; however, the ribosome is the only organelle that can be seen in both prokaryotic and eukaryotic cells.

Point to Remember: Eukaryotic ribosomes are much larger than Prokaryotic ones.

3. Identify the cell organelles labelled as A, B, C, and D. Mark the correct option w.r.t. organelle and its function.

Plant Cell

  1. A - Major site for synthesis of lipids.

  2. B - Performs the function of packaging materials, to be delivered to only intracellular targets.

  3. C - Sites of anaerobic respiration.

  4. D - Main arena of cellular respiration.

Ans: d. D - Main arena of cellular respiration.

The correct labelling of the diagram has been given below.

A - Endoplasmic Reticulum, B - Golgi apparatus, C - Mitochondria, D - Cytoplasm.

So, the main arena of cellular respiration is Cytoplasm.

Point to Remember: Glycolysis of aerobic respiration takes place in the cytoplasm of the cell. Also, Anaerobic respiration occurs at the same location. 


The article has given crisp and concise content as per the Cell - The Unit of Life NEET notes. The questions added at the end are highly important from the exam point of view and thus the student can have a clearer understanding of the type of questions that might appear in the exam. 

See More
NEET 2024 Important Dates

NEET 2024 Important Dates

View All Dates
NEET 2024 exam date and revised schedule have been announced by the NTA. NEET 2024 will now be conducted on 5 May 2024, and the exam registration starts on 9 February 2024 and closes on 9 March 2024. You can check the complete schedule on our site. Furthermore, you can check NEET 2024 dates for application, admit card, exam, answer key, result, counselling, etc along with other relevant information.
See More
View All Dates
NEET Information

NEET Information

Application Form
Eligibility Criteria
Reservation Policy
Admit Card
NTA has announced the NEET 2024 application form release date on the official website The NEET 2024 Application Form is available on the official website for online registration from 9 February 2024 to 9 March 2024. Besides the NEET 2024 application form release date, learn about the application process, steps to fill out the form, how to submit it, the exam date sheet, etc online. Check our website for more details.
NEET 2024 applicants should be aware of the eligibility criteria before applying for the exam. NTA has released all the relevant information on the official website, i.e. NEET 2024 aspirants should have passed Class 12th or any other equivalent qualifying examination in 2023, or 2022, or students appearing in the Class 12th final exam in 2024 can also apply. For further details, visit our website.
As per the union government’s norms, NTA has released the NEET 2024 reservation criteria for different candidates’ categories (SC/ST/OBC/PwD), All India Quota, State Government Quota, Deemed Universities, and more. You can check more details on the Vedantu website.
NEET 2024 Admit Card will be released by the NTA in the 4th week of April 2024. Candidates can download the NEET admit card and hall ticket from the NEET official website i.e. For more details on the NEET admit card 2024, candidates can check Vedantu's official website.
NEET 2024 Study Material

NEET 2024 Study Material

View NEET Syllabus in Detail
Download full syllabus
Download full syllabus
View NEET Syllabus in Detail
NEET 2024 Study Material

NEET 2024 Study Material

View all study material for NEET
See All
NEET Question Papers

NEET Question Papers

NEET 2024 Book Solutions and PDF Download

NEET 2024 Book Solutions and PDF Download

View all NEET Important Books
NCERT Book for Class 12 Biology
NCERT Book for Class 12 Physics
NCERT Book for Class 12 Chemistry
H. C. Verma Solutions
See All
NEET 2024 Mock Tests

NEET 2024 Mock Tests

View all mock tests
NEET 2024 free online mock test series for exam preparation are available on the Vedantu website for free download. Practising these mock test papers of Physics, Chemistry and Biology prepared by expert teachers at Vedantu will help you to boost your confidence to face the NEET 2024 examination without any worries. The NEET test series for Physics, Chemistry and Biology that is based on the latest syllabus of NEET and also the Previous Year Question Papers.
See More
NEET 2024 Cut Off

NEET 2024 Cut Off

NEET Cut Off
NTA is responsible for the release of the NEET 2024 cut off score. The qualifying percentile score might remain the same for different categories. According to the latest trends, the expected cut-off mark for NEET 2024 is 50% for general category candidates, 45% for physically challenged candidates, and 40% for candidates from reserved categories. For the general category, NEET qualifying marks for 2024 ranged from 715-117 general category, while for OBC/SC/ST categories, they ranged from 116-93 for OBC, 116-93 for SC and 116-93 for ST category.
See More
NEET 2024 Results

NEET 2024 Results

The NEET 2024 result will be published by NTA on in the form of a scorecard on 14 June 2024. The scorecard will include the roll number, application number, candidate's personal details, and the percentile, marks, and rank of the candidate. Only those candidates who achieve the NEET cut-off will be considered qualified for the exam.
See More
Rank List
Marks and Rank
NEET 2024 state rank lists will be released by the Medical Counselling Committee (MCC) for admissions to the 85% state quota and to all seats in private medical and dental colleges. NEET 2024 state rank lists are based on the marks obtained in medical entrance exams. Candidates can check the NEET 2024 state rank list on the official website or our site.
The Medical Counselling Committee (MCC) will conduct NEET 2024 counselling at There will be two rounds of counselling for admission under 15% All India Quota (AIQ), deemed and central universities, AIIMS, JIPMER, ESIC, and AFMC. A mop-up round of NEET counselling will be conducted excluding 15% AIQ seats, while the dates of NEET counselling for 85% state quota seats will be announced by the respective state authorities.
As per the union government’s norms, NTA has released the NEET 2024 reservation criteria for different candidates’ categories (SC/ST/OBC/PwD), All India Quota, State Government Quota, Deemed Universities, and more. Previously, the Indian Government has provided NEET reservations to OBC (27%) and EWS (10%) candidates under All India Quota (AIQ). You can check more details on the Vedantu website.
NEET 2024 Top Colleges

NEET 2024 Top Colleges

View all NEET 2024 Top Colleges
Want to know which Engineering colleges in India accept the NEET 2024 scores for admission to Engineering? Find the list of Engineering colleges accepting NEET scores in India, compiled by Vedantu. 1990 Colleges are accepting NEET Score. It includes 706 Medical, 323 Dental, 914 AYUSH, and 47 BVSc & AH colleges. Also find more details on Fees, Ranking, Admission, and Placement.
See More

FAQs on NEET Important Chapter: Cell - The Unit of Life


1. What are the major areas of the chapter that need to be learned on tips?

The student should remember the names of all the scientists involved, cell organelles and their respective functions, and the major theories as discussed in the chapter. 

2. What is the percentage weightage of chapter Cell - The Unit of Life in NEET?

The unit Cell: Structure and Function completely carries the 9% of weightage in NEET. This unit further carries 3 chapters, namely, Cell: the unit of life, Biomolecules, and Cell Cycle and Cell Division.

3. Is Biology difficult in NEET?

According to NEET research from past years, the exam is somewhat difficult. It has been observed that Physics stands as the most difficult section, while Biology was rated as the simplest.