NEET > Cell Structure and Function

Explore popular questions from Cell Structure and Function for NEET. This collection covers Cell Structure and Function previous year NEET questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

Which of the following cell organelles is responsible for extracting energy from carbohydrates to form ATP?

A

Ribosome

B

Chloroplast

Mitochondrion

D

Lysosome

Explanation

Mitochondria are miniature biochemical factories where food stuffs or respiratory substrates are completely oxidised to carbon dioxide and water. The energy liberated in the process is initially stored in the form of reduced coenzymes and reduced prosthetic groups. The latter soon undergo oxidation and form energy rich ATP. ATP comes out of mitochondria and helps perform various energy requiring processes of the cell like muscle contraction,nerve impulse conduction, biosynthesis, membrane transport, cell division, movement, etc. Because of the formation of ATP, the mitochondria are called power houses of the cell.

Q 2.    

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Incorrect-1

Select the mismatch.

A

Gas vacuoles - Green bacteria

Large central vacuoles - Animal cells

C

Protists - Eukaryotes

D

Methanogens - Prokaryotes

Explanation

Large central vacuole is the characteristic of plant cell, not animal cell which may have many small scattered vacuoles.

Q 3.    

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Incorrect-1

Select the wrong statement.

A

Bactetrial cell wall is made up of peptidoglycan.

Pili and fimbriae are mainly involved in motility of bacterial cells.

C

Cyanobacteria lack flagellated cells.

D

{tex}Mycoplasma{/tex} is a wall-less microorganism.

Explanation

Pili and fimbriae are bacterial appendages which are not involved in locomotion. Actually, pili are long fewer and thicker tubular outgrowths which develop in response to {tex} \mathrm { F } ^ { + } {/tex} 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.

Q 4.    

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Incorrect-1

A cell organelle containing hydrolytic enzymes is

lysosome

B

microsome

C

ribosome

D

mesosome.

Explanation

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 .

Q 5.    

Correct4

Incorrect-1

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?

(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.

Explanation

Both mitochondria and chloroplast are semi autonomous organelles. They have their own DNA which produces its own, {tex}m{/tex}RNA, {tex} t{/tex}RNA and {tex} r {/tex}RNA. These organelles also possess their own ribosomes and hence are able to synthesise some of their proteins.

Q 6.    

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Incorrect-1

Microtubules are the constituents of

A

centrioles, spindle fibres and chromatin

B

centrosome, nucleosome and centrioles

C

cilia, flagella and peroxisomes

spindle fibres, centrioles and cilia.

Explanation

Microtubules are unbranched hollow submicroscopic tubules of protein tubulin which develop on specific nucleating regions. It can undergo quick growth or dissolution at their ends by assembly or disassembly of monomers.
They are present in the cytoplasm as well as in specialised structures like centrioles, basal bodies, cillia or flagella, sensory hair, equatorial ring of thrombocytes, spindle apparatus, chromosome fibres, nerve processes, sperm tails, axostyle of parasitic flagellates, fibre system of {tex}Stentor{/tex}, cyto-pharyngeal basket of {tex}Nassula,{/tex} etc.

Q 7.    

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Incorrect-1

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

Lysosomes

B

Nuclei

C

Mitochondria

D

Chloroplasts

Explanation

Lysosomes are small vesicles bounded by a single membrane and contain hydrolytic enzymes. Nucleus, mitochondria and chloroplasts are double membrane bound cells organelles.

Q 8.    

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Incorrect-1

Match the columns and identify the correct option.


A

A - (iii), B - (i), C - (iv), D - (ii)

B

A - (iii), B - (iv), C - (ii), D - (i)

C

A - (iv), B - (iii), C - (i), D - (ii)

A - (iii), B - (iv), C - (i), D - (ii)

Explanation

Q 9.    

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Incorrect-1

Which of the following structures is not found in a prokaryotic cell?

A

Mesosome

B

Plasma membrane

Nuclear envelope

D

Ribosome

Explanation

A prokaryotic cell is characterised by absence of an organised nucleus and membrane bound cell organelles. DNA is naked {tex}i.e.,{/tex} without a nuclear envelope and lies variously coiled in the cytoplasm. It is commonly called nucleoid or genophore. Mesosomes, plasma membrane and 70 S ribosomes are present in a prokaryotic cell.

Q 10.    

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Incorrect-1

Cellular organelles with membranes are

A

endoplasmic reticulum, ribosomes and nuclei

lysosomes, Golgi apparatus and mitochondria

C

nuclei, ribosomes and mitochondria

D

chromosomes, ribosomes and endoplasmic reticulum.

Explanation

Endoplasmic reticulum, nuclei, lysosomes, Golgi apparatus and mitochondria are membrane bound cell organelles whereas ribosomes are naked ribonucleoprotein protoplasmic particles.Chromosomes are the hereditary particles present in the nucleus.

Q 11.    

Correct4

Incorrect-1

Which of the following are not membranebound?

A

Lysosomes

B

Mesosomes

C

Vacuoles

Ribosomes

Explanation

Endoplasmic reticulum, nuclei, lysosomes, Golgi apparatus and mitochondria are membrane bound cell organelles whereas ribosomes are naked ribonucleoprotein protoplasmic particles.Chromosomes are the hereditary particles present in the nucleus.

Q 12.    

Correct4

Incorrect-1

DNA is not present in

A

nucleus

B

mitochondria

C

chloroplast

ribosomes.

Explanation

Ribosome is a small spherical body within a living cell that is the site of protein synthesis. Ribosomes consist of two subunits, one large and one small, each of which comprises some RNA (called ribosomal RNA ) and protein. They do not have any DNA.

Q 13.    

Correct4

Incorrect-1

Nuclear envelope is a derivative of

A

microtubules

rough endoplasmic reticulum

C

smooth endoplasmic reticulum

D

membrane of Golgi complex.

Explanation

Recent developments have shown that nuclear membrane is derived from rough endoplasmic reticulum. During cell division, nuclear membrane is disintegrated. The nuclear envelope transmembrane proteins are absorbed in the RER. Once the division is completed, RER reassembles the nuclear envelope.

Q 14.    

Correct4

Incorrect-1

The structures that are formed by stacking of organised flattened membranous sacs in the chloroplasts are

A

stroma lamellae

B

stroma

C

cristae

grana.

Explanation

A chloroplast is a vesicle, bound by an envelope of two unit membranes and filled with a fluid matrix called stroma. The lamellae, after separation from the inner membrane, usually take the form of closed, flattened, ovoid sacs, the thylakoids, which lie closely packed in piles, the grana.

Q 15.    

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Incorrect-1

Select the correct matching in the following pairs.

A

Rough ER - Synthesis of glycogen

B

Rough ER - Oxidation of fatty acids

C

Smooth ER - Oxidation of phospholipids

Smooth ER - Synthesis of lipids

Explanation

Smooth endoplasmic reticulum (SER) is a system of smooth membranes ({tex}i.e.,{/tex} membranes not having ribosomes) within the cytoplasm of plant and animal cells. It forms a link between the cell and nuclear membranes. It is the site of important metabolic reactions, including phospholipid and fatty acid synthesis. In animal cells lipid-like steroidal hormones are also synthesized.

Q 16.    

Correct4

Incorrect-1

The chromosomes in which centromere is situated close to one end are

A

telocentric

B

sub-metacentric

C

metacentric

acrocentric.

Explanation

Centromere is a part of a chromosome that attaches to the spindle during cell division. A chromosome with the centromere close to one end is acrocentric.

Q 17.    

Correct4

Incorrect-1

Which one of the following is not an inclusion body found in prokaryotes?

A

Glycogen granule

Polysome

C

Phosphate granule

D

Cyanophycean granule

Explanation

Polysome is a not an inclusion body. It is an aggregation of ribosomes formed under conditions of high concentration of magnesium. An inclusion body is any of various particulate structures, usually proteins, formed after viral infections in a prokaryotic or eukaryotic cell.

Q 18.    

Correct4

Incorrect-1

The solid linear cytoskeletal elements having a diameter of 6 nm and made up of a single type of monomer are known as

A

microtubules

microfilaments

C

intermediate filaments

D

lamins.

Explanation

Microtubules are hollow microscopic tubular structures with an external diameter of 24 nm and of variable length. They are composed of tubulin. Intermediate filaments are the numerous microscopic protein fibres of about 10 nm thickness that form part of the cytoskeleton. They are made up of a variety of proteins {tex}e.g.{/tex} keratin in nails.

Q 19.    

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Incorrect-1

The osmotic expansion of a cell kept in water is chiefly regulated by

A

mitochondria

vacuoles

C

plastids

D

ribosomes.

Explanation

Vacuoles are non cytoplasmic areas present inside cytoplasm and separated from latter by tonoplast. They are believed to be formed by expansion and pinching off from ER. There occurs a large central vacuole and many small vacuoles in plant cells. They play a major role in osmotic expansion of cell.

Q 20.    

Correct4

Incorrect-1

Match the following and select the correctanswer.

Column IColumn II
A. Thylakoids(i) Disc-shaped sacs in Golgi apparatus
B. Cristae(ii) Condensed structure of DNA
C. Cisternae(iii) Flat membranous sacs in stroma
D. Chromatin(iv) Infoldings in mitochondria
(A) Centriole(i) Infoldings in mitochondira
(B) Chlorophyll(ii) Thylakoids
(C) Christae(iii) Nucleic acids
(D) Ribosomes(iv) Basal body of cilia or flagella

A - (iv), B - (ii), C - (i), D - (iii)

B

A - (i), B - (ii), C - (iv), D - (iii)

C

A - (i), B - (iii), C - (ii), D - (iv)

D

A - (iv), B - (iii), C - (i), D - (ii)

Explanation

Q 21.    

Correct4

Incorrect-1

The Golgi complex plays a major role

A

as energy transferring organelles

in post translational modification of proteins and glycosylation of lipids

C

in trapping the light and transforming it into chemical energy

D

in digesting proteins and carbohydrates.

Explanation

Post translational modification (PTM) is a step in protein biosynthesis. Proteins are created on ribosomes translating {tex}m{/tex}RNA into polypeptide chains. These polypeptide chains undergo PTM, such as folding, cutting and other processes, before becoming the mature protein product. Proteins synthesized by the rough endoplasmic reticulum and lipids synthesized by smooth endoplasmic reticulum reach the cisternae of the Golgi apparatus. Here, they combine with carbohydrates to form glycoproteins and glycolipids. This process is called glycosylation.

Q 22.    

Correct4

Incorrect-1

Which one of the following organelle in the figure correctly matches with its function?

A

Golgi apparatus,formation of glycolipids

Rough endoplasmic reticulum, protein synthesis

C

Rough endoplasmic reticulum, formation of glycoproteins

D

Golgi apparatus, protein synthesis

Explanation

The given figure shows endoplasmic reticulum bearing ribosomes on their surface. It is called rough endoplasmic reticulum or RER. RER is actively involved in protein synthesis and secretion.

Q 23.    

Correct4

Incorrect-1

A major site for synthesis of lipids is

A

symplast

B

nucleoplasm

C

RER

SER

Explanation

Smooth endoplasmic reticulum (SER) is a system of smooth membranes ({tex}i.e.,{/tex} membranes not having ribosomes) within the cytoplasm of plant and animal cells. It forms a link between the cell and nuclear membranes. It is the site of important metabolic reactions, including phospholipid and fatty acid synthesis. In animal cells lipid-like steroidal hormones are also synthesized.

Q 24.    

Correct4

Incorrect-1

The term 'glycocalyx' is used for

A

a layer present between cell wall and membrane of bacteria

B

cell wall of bacteria

C

bacterial cell glyco-engineered to possess N-glycosylated proteins

a layer surrounding the cell wall of bacteria.

Explanation

Glycocalyx is a sticky, gelatinous material that collects outside the cell wall of bacteria to form an additional surface layer. When this layer is firmly attached to the surface of the cell, it is called a capsule. If it is loosely distributed around the cell, the glycocalyx is called a slime layer.

Q 25.    

Correct4

Incorrect-1

Which of the following types of plastid does not contain stored food material?

Chromoplasts

B

Elaioplasts

C

Aleuroplasts

D

Amyloplasts

Explanation

Chromoplasts are yellow or reddish in colour because of the presence of carotenoid pigments. They do not contain stored food material. Chromoplasts are formed either from leucoplasts or chloroplasts. Chromoplasts provide colour to many flowers for attracting pollinating insects. They provide bright red or orange colour to fruits for attracting animals for dispersal.