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Biotechnology and Nanotechnology

11 questions

All types11Multiple choice6True / False4Matching1
Question 1Question →

In nanotechnology, Single-Walled Carbon Nanotubes (SWCNTs) exhibit uniform metallic conductivity across all structural configurations, irrespective of their chiral indices (n,m)(n, m), due to unconstrained π\pi-electron delocalization along their cylindrical lattice.

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Answer: False

Answer

The statement is False. The electrical conductivity of Single-Walled Carbon Nanotubes (SWCNTs) depends on their chiral indices (n,m)(n, m), making them either metallic or semiconducting.
The statement is false because the conductivity of SWCNTs is dictated by their chirality indices (n,m)(n, m). Only nanotubes satisfying the relation where (n−m)(n - m) is a multiple of 33 demonstrate metallic conductivity, whereas all other chiral arrangements produce semiconducting behavior.

Step-by-Step Solution

1
Analyze the structural synthesis of Single-Walled Carbon Nanotubes (SWCNTs).
SWCNTs can be conceptualized as a single-atom-thick graphene sheet rolled into a seamless cylinder along a specific chiral vector (n,m)(n, m).
The vector direction determines the circumferential alignment of carbon hexagons relative to the tube axis.
2
Evaluate the 1D quantum confinement effects on electronic band structures.
Rolling graphene imposes periodic boundary conditions along the circumference, quantizing wave vectors into 1D sub-bands.
Depending on whether these sub-bands pass through the Dirac points of graphene, the nanotube becomes metallic or semiconducting.
3
Apply the mathematical criterion for conductivity classification.
SWCNTs are metallic if (n−m)(n - m) is divisible by 33; otherwise, they exhibit a bandgap and function as semiconductors (comprising roughly two-thirds of all synthesized SWCNTs).
This structural dependence refutes the claim that all SWCNTs possess metallic conductivity regardless of chiral indices.

Key Concept

Chirality and Electronic Transport in Carbon Nanotubes
Question 2Question →

Somatic gene therapy targets non-reproductive cells of the body, and therefore any genetic modifications introduced during the treatment cannot be passed on to the patient's offspring.

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Answer: True

Answer

True
Somatic gene therapy targets non-germline body cells such as bone marrow, liver, or lung tissues. As a result, the therapeutic genetic edits remain confined to the patient and are not passed down to future generations. Inheritable genetic edits are exclusively achieved through germline gene editing.

Step-by-Step Solution

1
Identify the target cell type specified in somatic gene therapy.
Somatic gene therapy targets non-reproductive body cells (e.g., bone marrow, muscle, or respiratory cells).
Understanding cell type classification is essential to determine whether genetic changes can be inherited.
2
Evaluate the inheritability of genetic changes made to somatic cells.
Because germline cells (eggs and sperm) remain untouched, the genetic changes affect only the treated individual and cannot be inherited by offspring.
Only genetic alterations in reproductive (germline) cells are passed on to the next generation.

Key Concept

Distinction between somatic and germline gene therapy
Question 3Question →

With reference to recent developments in Biotechnology and Nanotechnology, consider the following statements:

1. Quantum dots are semiconductor nanocrystals whose fluorescence wavelength decreases as the particle size increases.
2. Somatic Cell Nuclear Transfer (SCNT) produces embryonic stem cells that inherit nuclear genomic DNA primarily from the somatic cell donor rather than the egg donor.
3. Carbon nanotubes can display either metallic or semiconducting electrical conductivity depending on their chiral angle and diameter.

Which of the statements given above is/are correct?

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Answer: 2 and 3 only

Answer

Statements 2 and 3 are correct, while Statement 1 is incorrect.
The option stating '2 and 3 only' is correct because Statement 2 accurately describes how SCNT transfers nuclear DNA from the somatic cell donor, and Statement 3 accurately describes chirality-governed electrical properties of carbon nanotubes. Statement 1 is false because larger quantum dots emit longer wavelengths (red-shift), not shorter wavelengths.

Step-by-Step Solution

1
Analyze Statement 1 regarding Quantum Dots and optical emission.
Statement 1 is incorrect. In quantum dots, confinement effects broaden the band gap as particle size decreases. Smaller dots emit higher-energy, shorter-wavelength light (blue light), whereas larger dots emit lower-energy, longer-wavelength light (red light).
Quantum confinement correlates bandgap energy inversely with nanoparticle size.
2
Analyze Statement 2 regarding Somatic Cell Nuclear Transfer (SCNT).
Statement 2 is correct. SCNT transfers a somatic nucleus into an enucleated oocyte, making the nuclear DNA virtually identical to the somatic donor cell.
The recipient egg cell contributes only cytoplasm and mitochondrial DNA, while the nuclear gene payload originates entirely from the somatic donor.
3
Analyze Statement 3 regarding Carbon Nanotubes (CNTs).
Statement 3 is correct. The orientation of the graphene roll (chirality vector (n,m)(n, m)) determines whether a single-walled carbon nanotube is metallic or semiconducting.
When (n−m)(n - m) is a multiple of 3, the CNT exhibits metallic conductivity; otherwise, it behaves as a semiconductor.

Key Concept

Quantum confinement in quantum dots, nuclear donor inheritance in SCNT, and chirality-dependent conductivity of carbon nanotubes
Question 4Question →

With reference to modern biotechnology, consider the following statements regarding CRISPR-Cas9 technology:

1. It functions as a precise genome-editing tool in living organisms.
2. The Cas9 enzyme acts as molecular scissors to cut target DNA sequences.

Which of the statements given above is/are correct?

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Answer: Both 1 and 2

Answer

Both statements 1 and 2 are correct.
Both statements are correct. CRISPR-Cas9 is a major biotechnological advancement adapted from bacterial immune systems. Guide RNA leads the complex to a complementary target sequence on the DNA strand, and the Cas9 enzyme acts as molecular scissors to cut the DNA, enabling precise genomic modifications.

Step-by-Step Solution

1
Evaluate Statement 1 regarding the application of CRISPR-Cas9.
Statement 1 is correct because CRISPR-Cas9 is widely used as a gene-editing technology to add, remove, or alter genetic material in organisms.
CRISPR enables precise modification of DNA sequences within genomes.
2
Evaluate Statement 2 regarding the specific role of the Cas9 component.
Statement 2 is correct because Cas9 is an endonuclease protein that cuts double-stranded DNA at targeted sites specified by guide RNA.
The endonuclease activity of Cas9 functions analogously to molecular scissors.

Key Concept

CRISPR-Cas9 Genome Editing Mechanism
Estimated Time:45s
Question 5Question →

In recombinant DNA technology, specific enzymes are utilized to precisely cut DNA strands at designated nucleotide recognition sites. Which of the following enzymes acts as 'molecular scissors' in genetic engineering?

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Answer: Restriction enzymes

Answer

Restriction enzymes act as the 'molecular scissors' in recombinant DNA technology by cleaving DNA molecules at specific recognition sequences.
Restriction enzymes, also known as restriction endonucleases, cut double-stranded DNA molecules at specific palindromic recognition sites. Because of this precise cutting action, they are universally termed 'molecular scissors' in biotechnology and genetic engineering.

Step-by-Step Solution

1
Identify the primary function of each enzyme listed in genetic engineering.
Restriction enzymes cut DNA, DNA ligase joins DNA, DNA polymerase synthesizes DNA strands, and reverse transcriptase synthesizes cDNA from RNA.
Matching each biological enzyme to its catalytic role clarifies which enzyme performs sequence-specific cleavage.
2
Select the enzyme corresponding to the 'molecular scissors' terminology.
Restriction endonucleases (restriction enzymes) fit this definition precisely.
The term 'molecular scissors' refers to enzymes that break phosphodiester bonds at specific target sequences within DNA.

Key Concept

Restriction Endonucleases in Biotechnology
Question 6Question →

Polymerase Chain Reaction (PCR) is a biotechnology technique primarily used to amplify specific segments of DNA, producing millions of copies from a tiny sample.

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Answer: True

Answer

The statement is True. Polymerase Chain Reaction (PCR) is a foundational molecular biotechnology technique designed to selectively amplify target DNA sequences into millions or billions of copies.
The statement is accurate because Polymerase Chain Reaction (PCR) is specifically designed to isolate and amplify designated regions of DNA, generating millions of identical copies for diagnostic and analytical applications.

Step-by-Step Solution

1
Identify the biotechnology process mentioned in the statement
The technique is Polymerase Chain Reaction (PCR).
Determining the primary function of PCR is necessary to assess the accuracy of the statement.
2
Analyze the core function and mechanism of PCR
PCR uses repeated thermal cycling, primers, and DNA polymerase to exponentially synthesize copies of a target DNA region.
This molecular copying mechanism allows micro-gram or nano-gram quantities of DNA to be multiplied rapidly.
3
Verify statement validity
The statement correctly describes DNA amplification via PCR.
The statement is confirmed to be True.

Key Concept

Polymerase Chain Reaction (PCR) and DNA Amplification
Question 7Question →

In bio-imaging applications, semiconductor quantum dots exhibit size-tunable fluorescence due to quantum confinement, wherein decreasing the nanoparticle radius increases its effective electronic energy bandgap, thereby causing the emitted fluorescence spectrum to shift toward longer wavelengths (red-shift).

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Answer: False

Answer

The statement is False. Decreasing the size of a quantum dot increases its energy bandgap, which results in the emission of higher-energy photons corresponding to shorter wavelengths (a blue-shift), not longer wavelengths.
Quantum dots display quantum confinement when their physical dimensions approach the exciton Bohr radius. Decreasing the particle size widens the energy gap between the valence and conduction bands. By the fundamental relation E=hcλE = \frac{hc}{\lambda}, a larger energy gap produces higher-energy, shorter-wavelength light (blue-shifted emission). Therefore, the assertion that an increased energy bandgap yields longer wavelengths (red-shift) is scientifically incorrect.

Step-by-Step Solution

1
Analyze the relationship between quantum dot physical size and energy bandgap.
As the radius of a semiconductor quantum dot decreases below its exciton Bohr radius, spatial confinement of charge carriers increases, widening the bandgap (EgE_g).
Quantum confinement alters the electronic band structure, causing energy levels to become discrete and expanding the energy gap between the valence and conduction bands.
2
Apply the Planck-Einstein energy-wavelength equation (E=hcλE = \frac{hc}{\lambda}) to relate energy bandgap to emission wavelength.
An increase in bandgap energy (EE) leads to a shorter emitted wavelength (λ\lambda).
Energy and wavelength are inversely proportional; thus, higher photon transition energies correspond to blue-shifted (shorter wavelength) light.
3
Evaluate the statement's conclusion regarding wavelength shift.
The statement incorrectly asserts that an increased energy bandgap causes a shift toward longer wavelengths (red-shift).
A shift toward longer wavelengths implies lower energy emission, which contradicts the established phenomenon of increased bandgap energy in smaller nanoparticles.

Key Concept

Quantum Confinement Effect and Size-Tunable Optical Emission in Quantum Dots
Question 8Question →

Consider the following statements regarding RNA Interference (RNAi) technology and nano-delivery systems in biotechnology:

1. RNA interference is a post-transcriptional gene silencing mechanism initiated by double-stranded RNA (dsRNA) molecules.
2. MicroRNAs (miRNAs) typically exhibit perfect sequence complementarity to a single specific target mRNA, leading to immediate enzymatic mRNA cleavage.
3. Lipid Nanoparticles (LNPs) act as delivery vehicles that protect delicate nucleic acids from degradation in extracellular fluids during systemic circulation.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

1 and 3 only
The correct answer states that 1 and 3 only are correct. RNAi is indeed a post-transcriptional silencing process driven by dsRNA, and Lipid Nanoparticles (LNPs) serve as crucial nanoscale delivery carriers that encapsulate RNA molecules to prevent extracellular degradation. Statement 2 is false because miRNAs usually bind with partial complementarity to exert translational repression, whereas perfect complementarity and direct mRNA cleavage are characteristic of siRNAs.

Step-by-Step Solution

1
Evaluate Statement 1 regarding RNA interference mechanism
Statement 1 is correct.
RNA interference (RNAi) is a conserved biological pathway where double-stranded RNA (dsRNA) triggers sequence-specific gene silencing at the post-transcriptional level.
2
Evaluate Statement 2 regarding miRNA complementarity and cleavage mechanism
Statement 2 is incorrect.
Small interfering RNAs (siRNAs) generally require full, perfect complementary binding to target specific mRNA for direct cleavage. MicroRNAs (miRNAs), on the other hand, typically possess partial or imperfect sequence complementarity, allowing them to target multiple distinct mRNAs and suppress translation rather than causing direct cleavage.
3
Evaluate Statement 3 regarding Lipid Nanoparticles (LNPs) as therapeutic delivery vehicles
Statement 3 is correct.
Lipid Nanoparticles (LNPs) shield sensitive nucleic acid payloads (such as siRNA or mRNA) from rapid enzymatic degradation by ribonucleases in systemic circulation and facilitate cellular uptake.

Key Concept

RNA interference mechanisms and nanomedicine drug delivery systems
Estimated Time:2m 0s
Question 9Question →

With reference to the applications of nanotechnology in biomedicine and healthcare, consider the following statements:

1. Gold nanoparticles exhibit localized Surface Plasmon Resonance (SPR), enabling their usage in high-sensitivity optical biosensors and targeted photothermal cancer therapy.
2. Liposomes are solid metallic nanostructures engineered to permanently integrate into host genome sequences during targeted drug delivery.
3. Dendrimers are highly branched, spherical synthetic macromolecules possessing well-defined molecular architectures that allow precise encapsulation of therapeutic agents for controlled drug release.

Which of the statements given above is/are correct?

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Answer: 1 and 3 only

Answer

1 and 3 only
The correct response identifies statements 1 and 3 as true while recognizing statement 2 as false. Gold nanoparticles utilize Surface Plasmon Resonance for diagnostics and hyperthermic tumor therapy, whereas dendrimers provide controlled drug loading due to their branched polymeric structure. Liposomes are lipid vesicles rather than metallic gene-altering particles.

Step-by-Step Solution

1
Evaluate Statement 1 regarding Gold Nanoparticles
Statement 1 is correct.
Gold nanoparticles undergo localized surface plasmon resonance (LSPR) when light interacts with conduction electrons on their surface, making them excellent candidates for biosensing, bio-imaging, and photothermal ablation of cancer cells.
2
Evaluate Statement 2 regarding Liposomes
Statement 2 is incorrect.
Liposomes are microscopic spherical vesicles composed of phospholipid bilayers surrounding an aqueous core. They are non-metallic lipid-based drug delivery vehicles and do not alter or integrate into host DNA.
3
Evaluate Statement 3 regarding Dendrimers
Statement 3 is correct.
Dendrimers are nanometer-scale, highly branched, 3D synthetic polymers with high functionality at their surface, ideal for drug encapsulation, targeted delivery, and gene therapy.

Key Concept

Nanomedicine and Nanobiotechnology Applications (Gold Nanoparticles, Liposomes, Dendrimers)
Question 10Question →

Match the advanced biotechnology and nanotechnology tools/materials in List I with their primary structural features or biomedical applications in List II:

Click a left item, then click its matching right item

Items

Fullerenes
Quantum Dots
Liposomes
Zinc Finger Nucleases

Matches

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Answer

Fullerenes correspond to spheroidal carbon cage structures with high electron affinity; Quantum Dots correspond to size-tunable semiconductor nanocrystals for fluorescent imaging; Liposomes correspond to spherical phospholipid bilayer vesicles encapsulating both hydrophilic and hydrophobic drugs; and Zinc Finger Nucleases correspond to engineered chimeric restriction proteins combining zinc-finger domains with FokI cleavage domains.
Each technology matches strictly with its defined mechanism: Fullerenes are closed carbon cages; Quantum Dots are fluorescence-tunable semiconductor nanocrystals; Liposomes are lipid bilayer vesicles for dual drug encapsulation; and Zinc Finger Nucleases are chimeric proteins combining zinc-finger DNA-binding motifs with FokI catalytic domains.

Step-by-Step Solution

1
Identify the structural nature of Fullerenes
Recognize Fullerenes as hollow carbon allotrope cages (e.g., C60) with antioxidant and carrier properties.
Fullerenes feature unique cage geometries capable of trapping species or acting as free radical scavengers.
2
Analyze Quantum Dots properties
Associate Quantum Dots with semiconductor nanocrystals whose narrow fluorescence emission varies with nanoparticle size.
Quantum confinement alters the energy bandgap as size changes, giving tunable optical properties for bio-labeling.
3
Examine Liposome architecture
Match Liposomes with self-assembled phospholipid bilayer spheres.
Their amphiphilic nature permits simultaneous transport of hydrophilic therapeutics in the interior and lipophilic therapeutics inside the lipid membrane.
4
Analyze Zinc Finger Nucleases structure
Link ZFNs to chimeric gene-editing tools formed by linking zinc-finger binding proteins with FokI cleavage domains.
ZFNs achieve site-specific double-strand DNA breaks via protein-DNA domain recognition paired with catalytic cleavage.

Key Concept

Classification and operating mechanisms of advanced bio-nanotechnology materials and genomic engineering tools
Question 11Question →

With reference to the applications of nanotechnology in modern agriculture, consider the following statements:

1. Nano-encapsulated pesticides allow targeted, controlled release of active chemical ingredients, thereby minimizing runoff and environmental contamination.
2. Nano-fertilizers increase nutrient uptake efficiency in crops by facilitating enhanced penetration through plant stomata and root membranes.
3. Nano-silver particles are widely incorporated into bio-fertilizers because they specifically promote the growth and colonization of beneficial nitrogen-fixing soil bacteria and mycorrhizal fungi.

Which of the statements given above is/are correct?

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Answer: 1 and 2 only

Answer

1 and 2 only
The correct response identifies Statements 1 and 2 as accurate applications of agri-nanotechnology. Controlled release via nano-capsules prevents environmental pollution, and small particle size boosts plant cellular transport. Statement 3 is false because silver nanoparticles exert toxic antimicrobial effects on symbiotic soil bacteria and fungi.

Step-by-Step Solution

1
Evaluate Statement 1 on nano-encapsulated pesticides
Statement 1 is correct.
Polymeric or lipid-based nano-encapsulation shields active pesticide molecules from premature chemical degradation (via UV or hydrolysis), enabling slow, site-specific delivery and reducing pesticide leaching.
2
Evaluate Statement 2 on nano-fertilizers nutrient uptake
Statement 2 is correct.
Due to their ultra-small size (<100 nm) and high surface area, nano-fertilizers pass through plant cuticle micro-pores and stomatal openings more efficiently than conventional macromolecular chemical fertilizers.
3
Evaluate Statement 3 on nano-silver interaction with beneficial soil microbes
Statement 3 is incorrect.
Nano-silver (AgNPs) releases silver ions (Ag+Ag^+) that disrupt bacterial cell walls and metabolic enzymes. Consequently, nano-silver exhibits non-selective bactericidal and fungicidal activity, which can inhibit beneficial soil bacteria (like Rhizobium and Azotobacter) and mycorrhizal fungi rather than promoting them.

Key Concept

Applications and ecotoxicology of agricultural nanotechnology (nano-fertilizers, nano-pesticides, and antimicrobial silver nanoparticles).
Biotechnology and Nanotechnology Practice Questions — State PSC Exam | Examkin