Cytology is the branch of biology that comprises the study of cell structure and its function. The structural and functional unit of all living beings is called cell. Cell has a dense membrane-bound structure called nucleus which contains the chromosomes which further contain the genetic material, DNA. 

• Mycoplasmas, the smallest cells, are only 0.3 µm in length while bacteria could be 3 to 5 µm. Nerve cells are the longest cells. These are some of the important points from this section that you must remember while preparing for NEET.
• Every year near about 6-7 questions are asked from this particular topic which means 10% is covered from this section. Check NEET Exam Pattern

Candidates should cover all the major topics from this section like plant cell, animal cell, Prokaryotic and Eukaryotic Cells, and much more. 

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What are the different types of Cells?

There are two types of cells: plant cell and animal cell.

Must Read: 

• NEET Study Notes for Molecular Basis of Inheritance
• NEET Study Notes for Biological Classification

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Prokaryotic and Eukaryotic Cells

Prokaryotic Cell

These are unicellular organisms, like, bacteria, blue-green algae, and mycoplasma. All prokaryotes have a cell wall that surrounds the cell membrane. 

Eukaryotic Cell

These cells include all the protists i.e. unicellular eukaryotes, plants, animals, and fungi. It contains hereditary material covered on the outside by a nuclear envelope. 

All eukaryotic cells are not identical, e.g., plant and animal cells.

Difference between Prokaryotic and Eukaryotic Cells

Sample Question

Q. In prokaryotic cells, ribosomes are

(a) 70 S

(b) 80 S

(c) 60S + 40S

(d) 50S + 40S

Solution. A

Cell Wall and the difference between its type

Cell wall is the outer most, protective, non living and supportive layer found in all the plant cells. It is not found in animal cells.

Plant cells can withstand a lot of variations in the surrounding medium as compared to animal cells because of cell walls.

Difference 

Plasma Memberane, Protoplasm, and Cytoplasm

Plasma Memberane

• Each and every living cell is covered by a thin transparent electron microscopic, elastic regenerative and selective permeable membrane called plasma membrane. It is quasi fluid in nature.
• Membranes also occur inside the cells. They are collectively called biomembranes.

Protoplasm

Protoplasm is a complex, granular, elastic colourless substance. It is selectively permeable. It is considered as “Polyphasic colloidal system”.

Cytoplasm

• The substance that occurs around the nucleus and inside the plasma membrane containing various organelles and inclusions is known as cytoplasm.

• It forms half of the cell’s volume and 90% of it is water. It contains ions, biomolecules, such as sugar, amino acid, nucleotide etc.

Sample Question

Q. The main arena of various types of activities of a cell is 

a) Plasma membrane

b) Mitochondrion

c) Cytoplasm

d) Nucleus

Solution. C

Mitochondria and Plastids

• Mitochondria are referred to as “powerhouse” of the cell and contain electron transport system. They have hollow sac like structures present in all eukaryotes except mature RBCs of mammals and sieve tubes of phloem.

• The mitochondria occur singly or in groups and their shape and size vary from cell to cell depending on physiological activity of cell.

• These are absent in all prokaryotes like bacteria and cyanobacteria.

Plastids

• Plastids, the term was first time used by Schimper and discovered by Haeckel are semiautonomous organelles having DNA, RNA, Ribosomes and double membrane envelope which store or synthesize various types of organic compounds as ATP.

• These are largest cell organelles in plant cell.

Sample Question

Q. DNA is present in

a) chromosomes and dictyosomes

b) chloroplasts and lysomes

c) mitochondria and chloroplasts

d) mitochondria and endoplasmic reticulum

Solution. C

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Difference between chlorophyll a and b

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Golgi Complex and its functions

Golgi complex also called “traffic police” of the cell is made up of various membranous system e.g. cisternae, vesicles and vacuoles.

Functions

• Secretion is the main function of golgi body.

• It is a large sized among the secretory cells.

• Glycosidation of lipids.

• Glycosylation of proteins.

• Helps in the formation of primary lysosomes.

Sample Question

Q. The Golgi complex plays a major role

a) In trapping the light & transforming it into chemical energy

b) In digesting proteins & carbohydrates

c) As energy transferring organelles

d) In post translational modification of proteins & glycosidation of lipids

Solution. D

Must Read: 

• NEET Study Notes for Ecosystem
• NEET Study Notes for Microbes in Human Welfare

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Lysosomes and its functions

Lysosomes popularly called "suicidal bags" are microscopic, vesicular structures of the cytoplasm, bounded by a single membrane.

These are absent in prokaryotes but are present in all eukaryotic animal cells except mammalian RBCs.

Types of lysosomes 

There are four types of lysosomes recognised :

• Primary lysosomes

• Secondary lysosomes 

• Tertiary lysosomes/Residual bodies

• Autophagosomes/Autolysosomes

Functions

• Lysosomes of sperm provide enzyme for breaking limiting membrane of egg e.g., hyaluronidase enzyme.

• Lysosomes function as trigger of cell division or initiate cell division by digesting repressor molecules.

• They also engulf the carcinogens.

Sample Question

Q. Which one of the following cell organelles is enclosed by a single membrane?

a) Chloroplasts

b) Lysosomes

c) Nuclei

d) Mitochondria

Solution. B

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Vacuole and its functions

The Vacuole is a non-living reservoir, bounded by a differentially or selectively permeable membrane, the tonoplast. These contain water, minerals and anthocyanin pigments.

The vacuoles may be sap vacuoles, contractile vacuoles or gas vacuoles.

Functions 

Vacuole maintains the osmotic relation of cell which is helpful in the absorption of water. The turgidity and flaccid stages of a cell are due to the concentrations of sap in the vacuole.

Sample Question

Q. The osmotic expansion of a cell which is kept in water is regulated by

a) Mitochondria

b) Vacuoles

c) Plastids

d) Ribosomes

Solution. B

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Nucleus and Structure of Chromosome and DNA

• It is a double membrane structure. The space between the two membrane is known as Perinuclear Space. 

• The two nuclear membrane are interrupted by minute pores called Nuclear Pores, which allows only certain molecules of particular size to enter the nucleus. The nuclear matrix is known as Nucleoplasm. Nucleoplasm is composed of chromatin and nucleolus.

Structure of Chromosome and DNA

• Chromatin is a network of DNA which is surrounded by proteins known as Histone Proteins. During no cell division, the genetic material exists in the form of chromatin. 

Sample Question

Q. Controlling centre of cell is

A) Nucleus 

B) Nucleolus 

C) Mitochondria 

D) Ribosome 

Solution. A

Important Topics in Cell Biology

Candidates must go through the topics given below before the exam to score good marks in this section.

• Cells, Cell Division, Animal Cell, Plant Cell, Cell Wall, Cell Wall and Cell Membrane
• Cytoplasm, Cytoskeleton, Mitochondria, Ribosomes, Centrosome, Plastids, Vacuoles
• Prokaryotic cell, Endoplasmic Reticulum, Golgi Apparatus, The Nucleus, Microbodies
• Difference Between Mitochondria and Chloroplast
• Difference Between Mitochondria And Plastids
• Difference between Cell and Tissue
• Difference Between Nucleus And Nucleoid
• Difference Between Cell Membrane and Plasma Membrane
• Difference Between Unicellular And Multicellular Organisms
• Difference between Prokaryotic and Eukaryotic Cells
• Difference Between Plant cell and Animal cell

Must Read: 

• NEET Study Notes for Plant Kingdom
• NEET Study Notes for Strategies of Enhancement of Food
• NEET Study Notes for Genetics

Study Plan for NEET Biology

Candidates can make a study plan. Even the revisions need to be planned so that you can cover all the topics. Candidates can follow the given below plan which will be helpful for them.

• Week 1 

Select one to two topics daily and give 1-hour each to revise theses topics. 

• Week 2 

After revising the basics, learn or go through all the topic wise formulae and make sure you write and learn.

• Week 3 

Try to solve at least 30-40 questions within 1 to 2 hours.

• Week 4 

Take the previous year’s papers. Select one Topic and Identify the questions based on that topic. Try to solve these questions to improve your speed.

• Week 5 

Give as many Mock Tests as possible daily.

• Week 6

Go for Last and Final Revision.

Check Detailed Study Plan for NEET 2021

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Previous Year Solved Sample Questions

Q. A difference between eukaryotic and prokaryotic cells is in having

(a) Ribosomes

(b) Cell wall

(c) Nuclear membrane

(d) None of the above

Solution. C

Q. The two domains to which prokaryotes are classified into are:

(a) Bacteria and Protista

(b) Bacteria and Archaea

(c) Archaea and Eukarya

(d) Eukarya and Monera

Solution. B

Q. Which of the following has its own DNA? 

a) Mitochondria

b) Dictyosome

c) Lysosome

d) Peroxisome

Solution. A

Q. A cell organelle containing hydrolytic enzyme is 

a) Lysosome

b) Microsome

c) Ribosome

d) Mesosome

Solution. A

Q. The function of nucleolus is the synthesis of

A) DNA 

B) m-RNA 

C) r-RNA 

D) t-RNA 

Solution. C

Download NEET Practice paper

Tricks for NEET Biology

Candidates can go through some tricks given below to study Biology while preparing for NEET 2021

• Candidates must revise all diagrams and tables from NCERT books thoroughly.
• Read examples for the various topics like plant kingdoms, animal kingdom and animal tissue etc. from NCERT book.
• Learn the different genetic combinations. 
• Practise NCERT based questions as much as you can.
• Revise the scientific names again and again.