NEET Previous Year Questions (2016-2024): Cell: The Unit of Life | Biology Class 11 PDF Download

2024

Q1: Match List I with List II       (NEET 2024)

Choose the correct answer from the options given below:
(a)  A-III, B-II, C-IV, D-I
(b) A-II, B-III, C-I, D-IV
(c) A-III, B-IV, C-II, D-I
(d) A-I, B-II, C-III, D-IV
Ans: (a)
Let's analyze each item in List I and the correct match in List II.

Nucleolus (A) is primarily known as the site where ribosomal RNA (rRNA) is synthesized and where initial ribosome assembly occurs. Thus, it matches perfectly with III. Site of active ribosomal RNA synthesis.
Centriole (B) is a cylindrical cellular structure composed of microtubules and is best known for its role in facilitating cell division, especially in the formation of the spindle apparatus. Its structure is often described as being like a cartwheel, which makes it accurately matched with II. Organization like the cartwheel.

Leucoplasts (C) are a type of non-pigmented plastid found in plant cells, primarily involved in the storage of important nutrients such as starch, oils, and proteins. Hence, the appropriate pair is IV. For storing nutrients.

Golgi apparatus (D) functions in the sorting, modifying, and packaging of macromolecules for cell secretion or for use within the cell. It includes the synthesis of glycolipids among its activities. Consequently, the correct match is I. Site of formation of glycolipid.

With these correlations, the correct matches are:

• A - III,
• B - II,
• C - IV,
• D - I

Therefore, the correct option is Option A: A-III, B-II, C-IV, D-I.

Q2: The DNA present in chloroplast is:      (NEET 2024)
(a) Linear, double stranded
(b) Circular, double stranded
(c) Linear, single stranded
(d) Circular, single stranded
Ans: (b)
Chloroplasts are organelles found in the cells of plants and of some other organisms that carry out photosynthesis. They contain their own genetic material, separated from the DNA found in the nucleus of the cell. The DNA in chloroplasts has a distinct structure and form.

The DNA within chloroplasts is mostly:

• Circular: The DNA forms a closed loop, similar to the DNA found in bacteria. This similarity supports the endosymbiotic theory, which proposes that chloroplasts originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells.
• Double-stranded: Like most DNA, the DNA in chloroplasts is made up of two complementary strands that wind around each other to form a double helix.
  Based on this information, the correct answer to your query about the form of DNA present in chloroplasts is: Option B: Circular, double stranded

Q3:  Given below are two statements:
Statement I: Mitochondria and chloroplasts both double membranes bound organelles.
Statement II: Inner membrane of mitochondria is relatively less permeable, as compared chloroplast.

In the light of the above statements, choose the mis appropriate answer from the options given below:
(a) Both Statement I and Statement II are correct.
(b) Both Statement I and Statement II are incorrect.
(c) Statement I is correct but Statement II is incorrect.
(d) Statement I is incorrect but Statement II is correct.
Ans: (c)
Both mitochondria and chloroplasts are double membrane bound cell organelles.

Transport of ions occurs across the inner membrane of mitochondria. The inner membrane of chloroplast is impermeable to ions and metabolites. Therefore, it is said that inner membrane of mitochondria is relatively more permeable to that of chloroplast.

Q4: Match List I with List-II :     (NEET 2024)

Choose the correct answer from the options given below :
(a) A-IV, B-III, C-II, D-I
(b) A-IV, B-II, C-III, D-I
(c) A-II, B-IV, C-I, D-III
(d) A-II, B-I, C-IV, D-III
Ans: (d)
The correct matching between List I and List II can be understood by knowing the respective functions or structural components of the mentioned items:

• Axoneme: This is the core of cilia or flagella, consisting of microtubules arranged in a characteristic pattern. This hence matches with II 'Cilia and flagella'.
• Cartwheel pattern: The term 'cartwheel structure' is specifically associated with the central hub of the centriole's microtubule triplet arrangements in cellular structures. Therefore, this matches with I 'Centriole'.
• Crista: Cristae are the internal membranes of mitochondria that are folded into ridges, involved in the mitochondrial energy generation. Therefore, C matches with IV 'Mitochondria'.
• Satellite: In a cellular context, satellites typically refer to certain types of secondary structures or appendages associated with nucleic acids, hence best matching with III 'Chromosome'.

Thus, matching the correct items gives us: A-II, B-I, C-IV, D-III.

This corresponds to Option D.

2023

Q1: In tissue culture experiments, leaf mesophyll cells are put in a culture medium to form callus. This phenomenon may be called as
(a) Dedifferentiation
(b) Development
(c) Senescence
(d) Differentiation                  (NEET 2023)
Ans: (a)

• In tissue culture experiments, leaf mesophyll cells are put in a culture medium to form callus. This phenomenon may be called as dedifferentiation.
• Dedifferentiation is a phenomenon by which the living differentiated plant cells, that by now have lost the capacity to divide can regain the capacity of division under certain conditions.

Q3: Which of the following are NOT considered as the part of endomembrane system?    (NEET 2023)
A. Mitochondria
B. Endoplasmic reticulum
C. Chloroplast
D. Golgi Complex
E. Peroxisomes
(a) B & D only
(b) A, C & E only
(c) A & D only
(d) A, D & E only
Ans: (b)
The endomembrane system in a cell includes:
- The nuclear envelope
- The endoplasmic reticulum (ER)
- The Golgi apparatus (Golgi complex)
- Lysosomes
- Vesicles
- The plasma membrane
This system is involved in the modification, packaging, and transport of proteins and lipids.
Mitochondria and chloroplasts are not part of the endomembrane system. They are both organelles with their own separate membranes, and they have their own DNA. They are thought to have originated from a symbiotic relationship with prokaryotic cells, a theory known as endosymbiosis.
Peroxisomes, although they are membrane-bound organelles involved in many metabolic reactions, are also not considered part of the endomembrane system because they do not communicate with the other endomembrane organelles and are not involved in protein sorting or lipid synthesis like the other components of the endomembrane system.

Q4: Which of the following functions is carried out by cytoskeleton in a cell?    (NEET 2023)
(a) Nuclear division
(b) Protein synthesis
(c) Motility
(d) Transportation
Ans: (c)
An elaborate network of filamentous proteinaceous structures consisting of microtubules, microfilaments and intermediate filaments present in cytoplasm is collectively referred to as the cytoskeleton. It is involved in many functions such as mechanical support, motility, maintenance of the shape of the cell.

2022

Q1: Which of the following statements with respect to the endoplasmic reticulum is incorrect?    (NEET 2022 Phase 1)
(a) SER is devoid of ribosomes
(b) In prokaryotes only RER are present
(c) SER are the sites for lipid synthesis
(d) RER has ribosomes attached to ER
Ans: (b)
Presence of membranous organelles is an exclusive property of eukaryotic cells. Endoplasmic reticulum is an example of membranous organelles, so, it will always be found in eukaryotic cells only and never in the prokaryotes. This is true for SER and RER both. 

Q2: The Phenomenon by which the undividing parenchyma cells start to divide mitotically during plant tissue culture is called as
(a) Secondary growth
(b) Differentiation
(c) Dedifferentiation
(d) Redifferentiation    (NEET 2022 Phase 2)
Ans: (c)
The phenomenon where certain living differentiated cells regain or attain their ability to divide and form new cells is known as dedifferentiation.

Q3: Match List-I with List-II  (NEET 2022 Phase 2)

Choose the correct answer from the options given below.
(a) (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
(b)(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
(c) (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
(d) (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
Ans: (c)

• Porins are huge pores in outer membrane of mitochondria.
• Leg haemoglobin turns the nodules pink in colour.
• H⁺ accumulation in lumen of thylakoid occurs during photosynthetic electron transport.
• Respiration is an amphibolic pathway.

Q4: Which type of substance would face difficulty to pass through the cell membrane?    (NEET 2022 Phase 2)
(a) Substance soluble in lipids
(b) Substance with hydrophobic moiety
(c) Substance with hydrophilic moiety
(d) All substance irrespective of hydrophobic and hydrophilic moiety
Ans: (c)
Substances that have a hydrophilic moiety find it difficult to pass through the plasma membrane; thus, their movement has to be facilitated.

Q5: If the pH in lysosomes is increased to alkaline, what will be the outcome?   (NEET 2022 Phase 2)
(a) Lysosomal enzymes will be more active
(b) Hydrolytic enzymes will function more efficiently
(c) Hydrolytic enzymes will become inactive
(d) Lysosomal enzymes will be released into the cytoplasm
Ans: (c)

• Sol. Lysosomes contain hydrolytic enzymes which become active at acidic pH.
• If pH in lysosomes is increased to alkaline or basic then hydrolytic enzymes will become inactive.

2021

Q1: When the centromere is situated in the middle of two equal arms of chromosomes, the chromosome is referred as:    (NEET 2021)
(a) Sub-metacentric
(b) Acrocentric
(c) metacentric
(d) Telocentric
Ans: (c)

• When the centromere is situated in the middle of two equal arms of chromosomes, the chromosome is referred as Metacentric.
• When the centromere is present slightly away from the middle, it is called sub-metacentric chromosome.
• When the centromere is present very close to one end of the chromosome, it is called acrocentric chromosome.
• When the centromere is present at terminal position, the chromosome is called telocentric.

Q2: Match List - I with List - II    (NEET 2021)

Choose the correct answer from the options given below.
      (a)      (b)       (c)     (d)
(a) (iii)      (iv)      (i)      (ii)
(b) (ii)       (iii)     (iv)     (i)
(c) (iv)      (iii)      (ii)      (i)
(d) (i)       (iv)      (iii)     (ii)
Ans: (a)

• The inner membrane of mitochondria forms infoldings called cristae.
• Thylakoids are flattened membranous sacs in stroma of plastids.
• Cisternae are disc shaped sacs in Golgi apparatus.
• Primary constriction in chromosome that holds two chromatids together is called centromere.

Hence, correct option is (d)- a(iii), b(iv), c(i), d(ii)

Q4: The organelles that are included in the endomembrane system are:    (NEET 2021)
(a) Golgi complex, Mitochondria, Ribosomes and Lysosomes
(b) Golgi complex, Endoplasmic reticulus, Mitochondria and Lysosomes
(c) Endoplasmic reticulum, Mitochondria, Ribosomes and Lysosomes
(d) Endoplasmic reticulum, Golgi complex, Lysosomes and Vacuoles
Ans: (d)

• Endomembrane system consist of endoplasmic reticulum, Golgi complex, vacuoles and lysosomes.
• Mitochondria is semi-autonomous cell organelle.
• Ribosome is non-membranous cell organelle.

2020

Q1: Which of the following statements about inclusion bodies is incorrect?    (NEET 2020)
(a) They lie free in the cytoplasm
(b) These represent reserve material in cytoplasm.
(c) They are not bound by any membrane.
(d) These are involved in ingestion of food particles.
Ans: (d)
Inclusion bodies are nuclear or cytoplasmic aggregates which are stainable substances, usually proteins, and formed due to viral multiplication or genetic disorders in human beings these bodies are either intracellular or extracellular abnormalities and they are specific to certain diseases. These are not involved in ingestion of food particles.

Q2: Which is the important site of formation of glycoproteins and glycolipids in eukaryotic cells?    (NEET 2020)
(a) Golgi bodies
(b) Polysomes
(c) Endoplasmic reticulum
(d) Peroxisomes
Ans: (a)
Golgi bodies are site of formation of glycoproteins and glycolipids in eukaryotic cells.

2019

Q1: Which of the following pairs of organelles does not contain DNA?    (NEET 2019)
(a) Nuclear envelope and Mitochondria
(b) Mitochondria and Lysosome
(c) Chloroplast and Vacuoles
(d) Lysosomes and Vacuoles
Ans: (d)
Lysosome and vacuoles do not contain DNA.

Q2: Which of the following statements regarding mitochondria is incorrect?    (NEET 2019)
(a) Mitochondrial matrix contains single circular DNA molecule and ribosomes.
(b) Outer membrane is permeable to monomers of carbohydrates, fats and proteins.
(c) Enzymes of electron transport are embedded in outer membrane.
(d) Inner membrane is convoluted with infoldings.
Ans: (c)
The enzymes required for the ETS are present in the inner matrix only as the elementary particles are embedded in the inner membrane of the mitochondrial matrix.

Q3: Which of the following statements is not correct?    (NEET 2019)
(a) Lysosomes are formed by the process of packaging in the endoplasmic reticulum.
(b) Lysosomes have numerous hydrolytic enzymes.
(c) The hydrolytic enzymes of lysosomes are active under acidic pH.
(d) Lysosomes are membrane-bound structures.
Ans: (a)
Lysosomes are indeed membrane-bound structures (Option A) that contain numerous hydrolytic enzymes (Option C) which are active under acidic conditions (Option D). However, lysosomes are not formed by the endoplasmic reticulum. Instead, they are formed from vesicles that bud off from the Golgi apparatus. The endoplasmic reticulum is involved in the synthesis of proteins, some of which are destined for lysosomes, but the actual formation and packaging of lysosomes occur at the Golgi apparatus.

2018

Q1: Which of the following is true for nucleolus?    (NEET 2018)
(a) Larger nucleoli are present in dividing cells.
(b) It is a membrane-bound structure.
(c) It takes part in spindle formation.
(d) It is a site for active ribosomal RNA synthesis.
Ans: (d)
The nucleolus (plural nucleoli) is a large, distinct, spheroidal subcompartment of the nucleus of eukaryote cells that is the site of ribosomal RNA (rRNA) synthesis and assembly of ribosomal subunits.

Q2: The Golgi complex participates in    (NEET 2018)
(a) Fatty acid breakdown
(b) Formation of secretory vesicles
(c) Respiration in bacteria
(d) Activation of amino acid.
Ans: (b)
The Golgi apparatus receives proteins and lipids from the ER. It modifies them, concentrates and packs them into secretory vesicles that are formed by budding off from the trans-Golgi surface.

Q3: Which of the following events does not occur in rough endoplasmic reticulum?    (NEET 2018) 
(a) Protein folding
(b) Protein glycosylation
(c) Cleavage of signal peptide
(d) Phospholipid synthesis
Ans: (d)
Phospholipid synthesis does not take place in rough endoplasmic reticulum (RER). Smooth endoplasmic reticulum (SER) is involved in lipid synthesis.

Q4: Select the incorrect match.    (NEET 2018)
(a) Lampbrush chromosomes - Diplotene bivalents
(b) Allosomes - Sex chromosomes
(c) Sub-metacentric chromosomes - L-shaped chromosomes
(d) Polytene chromosomes - Oocytes of amphibians
Ans: (d)
Polytene chromosomes are found in salivary glands of insects and are also called as salivary chromosomes.

2017

Q1: Which of the following cell organelles is responsible for extracting energy from carbohydrates to form ATP?    (2017)
(a) Ribosome
(b) Chloroplast
(c) Mitochondrion
(d) Lysosome
Ans: (c)
The site of aerobic oxidation of carbohydrates in cells to generate ATP are mitochondria.

2016

Q1: A cell organelle containing hydrolytic enzymes is    (NEET 2016 Phase 2)
(a) Lysosome
(b) Microsome
(c) Ribosome
(d) Mesosome
Ans: (a)
Lysosomes are small vesicles which are bounded by a single membrane and contain hydrolytic enzymes in the form of minute crystalline or semicrystalline granules of 5 - 8 nm. About 50 enzymes have been recorded to occur in them. All the enzymes do not occur in the same lysosome but there are different sets of enzymes in different types of lysosomes. The important enzymes are acid phosphatases, sulphatases, proteases, peptidases, nucleases, lipases and carbohydrases. They are also called acid hydrolases because these digestive enzymes usually function in acidic medium or pH of 4 - 5.

Q2: Select the mismatch.    (NEET 2016 Phase 2)
(a) Gas vacuoles - Green bacteria
(b) Large central vacuoles - Animal cells
(c) Protists - Eukaryotes
(d) Methanogens - Prokaryotes
Ans: (b)
Large central vacuole is the characteristic of plant cell, not animal cell which may have many small scattered vacuoles.

Q3: Select the wrong statement.   (NEET 2016 Phase 2)
(a) Bacterial cell wall is made up of peptidoglycan.
(b) Pili and fimbriae are mainly involved in motility of bacterial cells.
(c) Cyanobacteria lack flagellated cells.
(d) Mycoplasma is a wall-less microorganism.
Ans: (b)
Pili and fimbriae are bacterial appendages which arc not involved in locomotion. Actually, pili are long, fewer and thick tubular outgrowths which develop in response to F⁺ or fertility factor in Gram negative bacteria. Being long they are helpful in attaching to recipient cell and forming conjugation tube. Fimbriae are small bristle-like fibres sprouting from cell surface in large number. There are 300-400 of them per cell. They are involved in attaching bacteria to solid surfaces.

Q4: Mitochondria and chloroplast are
(A) Semi-autonomous organelles
(B) Formed by division of pre-existing organelles and they contain DNA but lack protein synthesising machinery.
Which one of the following options is correct?     (NEET 2016 Phase 1)
(a) (A) is true but (B) is false.
(b) Both (A) and (B) are false.
(c) Both (A) and (B) are correct.
(d) (B) is true but (A) is false.
Ans: (a)
Mitochondria & chloroplast are semiautonomous cell organelle which are formed by division of pre-existing organelle & contain DNA but they also contain protein synthesizing machinery, thus (a) is true & (b) is false.

Q5: Microtubules are the constituents of    (NEET 2016 Phase 1)
(a) Centrioles, spindle fibres and chromatin
(b) Centrosome, nucleosome and centrioles
(c) Cilia, flagella and peroxisomes
(d) Spindle fibres, centrioles and cilia.
Ans: (d)
Microtubules are long, hollow cylinders made up of polymerised α- and β-tubulin dimers. Microtubules are part of a structural network (the cytoskeleton) within the cell’s cytoplasm. Roles of the microtubule cytoskeleton include mechanical support, organization of the cytoplasm, transport, motility and chromosome segregation so they are present in cilia and flagella for cellular movement, centrioles for chromosomal movement and spindle fibres for structural organization as well as chromosomal movement during nuclear division.

Q6: Which one of the following cell organelles is enclosed by a single membrane?     (NEET 2016 Phase 1)
(a) Lysosomes
(b) Nuclei
(c) Mitochondria
(d) Chloroplasts
Ans: (a)
Double Membrane bound Organelles: Mitochondria, Chloroplasts, Endoplasmic Reticulum, Golgi Body, and Nucleus. Single Membrane bound Organelles: Lysosomes, Peroxisomes, and Vacuoles. Organelles lacking any membrane: Ribosomes, Centrioles, Nucleolus.