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Which functional group is characteristic of beta-lactam antibiotics like penicillin?
- Ester
- Amide
- Beta-lactam ring
- Carboxylic acid
Answer: Beta-lactam ring
Beta-lactam ring (4-membered cyclic amide) inhibits bacterial cell wall synthesis. Resistance via beta-lactamase enzymes. Core structure for penicillins, cephalosporins, carbapenems. [[NCERT Chemistry Class 12]]
Incineration of municipal solid waste primarily produces energy in the form of ________.
- Biogas
- Electricity
- Hydrogen
- Ethanol
Answer: Electricity
Waste incineration burns MSW to generate steam, driving turbines for electricity. Reduces landfill volume but requires emission controls. Part of integrated waste management. [[MoEFCC Guidelines]]
True or False: Perovskite solar cells have achieved laboratory efficiencies exceeding 25%.
- True
- False
Answer: True
Perovskite PV cells (hybrid organic-inorganic) offer high efficiency, low cost, and flexibility. Challenges: stability, scalability. India's National Solar Mission supports R&D in next-gen PV. [[MNRE Reports]]
Which tool is used to create a bit-by-bit copy of a storage device for forensic analysis?
- Antivirus
- Disk imaging software
- Firewall
- Encryption tool
Answer: Disk imaging software
Forensic imaging (e.g., FTK Imager, dd) creates exact clones preserving metadata and deleted files. Essential for legal evidence collection without altering original data. [[CERT-In Guidelines]]
DNA methylation typically occurs at ________ dinucleotide sites and generally represses gene expression.
- AT
- GC
- CG
- TA
Answer: CG
CpG islands (CG dinucleotides) are common methylation sites. Methyl groups added to cytosine by DNMT enzymes silence genes. Epigenetic changes influence development, disease, and inheritance. [[NCERT Biology Class 12]]
True or False: Host-guest chemistry is a branch of supramolecular chemistry focusing on non-covalent interactions.
- True
- False
Answer: True
Supramolecular chemistry studies molecular assemblies via hydrogen bonds, van der Waals, π-π interactions. Applications: drug delivery, sensors, molecular machines (Nobel 2016). [[NCERT Chemistry Class 12]]
Which pollutant is NOT directly measured by the National Air Quality Index (NAQI)?
- PM2.5
- Ozone (O₃)
- Carbon Monoxide (CO)
- Carbon Dioxide (CO₂)
Answer: Carbon Dioxide (CO₂)
NAQI monitors 8 pollutants: PM10, PM2.5, NO₂, SO₂, CO, O₃, NH₃, Pb. CO₂ is a greenhouse gas but not a criteria air pollutant for NAQI. Important distinction for environmental exams. [[CPCB Guidelines]]
Graphene is a single layer of carbon atoms arranged in a ________ lattice.
- Cubic
- Hexagonal
- Tetragonal
- Orthorhombic
Answer: Hexagonal
Graphene's 2D honeycomb lattice gives exceptional strength, conductivity, and flexibility. Applications: flexible electronics, composites, sensors. Nobel Prize in Physics 2010. [[NCERT Chemistry Class 11, DST Reports]]
True or False: AI algorithms can assist in early detection of diseases like diabetic retinopathy from retinal scans.
- True
- False
Answer: True
Deep learning models (e.g., CNNs) analyze medical images with accuracy comparable to specialists. India's AI for All strategy promotes such applications for affordable healthcare. [[NITI Aayog, MoHFW Reports]]
Which neurotransmitter is primarily associated with reward and pleasure pathways?
- Serotonin
- Dopamine
- GABA
- Acetylcholine
Answer: Dopamine
Dopamine in mesolimbic pathway mediates reward, motivation, addiction. Imbalances linked to Parkinson's (deficit) and schizophrenia (excess). Critical for understanding brain function. [[NCERT Biology Class 11]]
Biodegradable polymers like PLA (Polylactic Acid) are derived from renewable resources such as ________.
- Petroleum
- Corn starch
- Coal
- Natural gas
Answer: Corn starch
PLA is synthesized from lactic acid produced by fermenting corn starch/sugarcane. Degrades to CO₂ and water under composting conditions. Sustainable alternative to conventional plastics. [[NCERT Chemistry Class 12]]
True or False: Circular economy aims to eliminate waste by designing products for reuse, repair, and recycling.
- True
- False
Answer: True
Circular economy contrasts linear 'take-make-dispose' model. Principles: design out waste, keep materials in use, regenerate natural systems. India's Resource Efficiency Strategy promotes this. [[NITI Aayog Reports]]
Aditya-L1, India's solar mission, is positioned at which Lagrange point?
- L1
- L2
- L4
- L5
Answer: L1
Aditya-L1 orbits Sun-Earth L1 point (~1.5 million km from Earth), providing uninterrupted solar observation. Studies corona, solar winds, and space weather impacts. [[ISRO Reports, NCERT Geography Class 11]]
Geostationary satellites orbit at approximately ________ km above Earth's equator.
- 360
- 3600
- 36000
- 360000
Answer: 36000
Geostationary orbit (GEO) at ~35,786 km altitude matches Earth's rotation period (24h), so satellite appears fixed. Used for TV broadcasting, weather monitoring, communication. [[ISRO Reports, NCERT Physics Class 11]]
True or False: Induced pluripotent stem cells (iPSCs) are derived from adult somatic cells reprogrammed to an embryonic-like state.
- True
- False
Answer: True
iPSCs (Yamanaka, 2006) are generated by introducing transcription factors (Oct4, Sox2, Klf4, c-Myc) into adult cells. Avoid ethical issues of embryonic stem cells; used in regenerative medicine. [[DBT Reports, NCERT Biology Class 12]]
Which drug class inhibits the enzyme ACE (Angiotensin-Converting Enzyme)?
- Beta-blockers
- ACE inhibitors
- Calcium channel blockers
- Diuretics
Answer: ACE inhibitors
ACE inhibitors (e.g., Enalapril, Lisinopril) block conversion of angiotensin I to II, lowering blood pressure. First-line treatment for hypertension and heart failure. [[NCERT Biology Class 11, MoHFW Guidelines]]
Reverse osmosis (RO) membranes remove dissolved salts by applying pressure greater than the ________ pressure.
- Atmospheric
- Osmotic
- Vapor
- Hydrostatic
Answer: Osmotic
RO forces water through semi-permeable membrane against osmotic gradient, rejecting ions/molecules. Widely used for desalination and water purification. [[CPCB Guidelines, NCERT Chemistry Class 12]]
True or False: Quantum dots exhibit size-dependent optical properties due to quantum confinement.
- True
- False
Answer: True
Quantum dots (semiconductor nanocrystals) emit different colors based on size: smaller dots emit blue, larger emit red. Used in displays, bioimaging, solar cells. [[NCERT Physics Class 12, DST Reports]]
Which encryption method uses a pair of public and private keys?
- Symmetric encryption
- Asymmetric encryption
- Hashing
- Steganography
Answer: Asymmetric encryption
Asymmetric (public-key) cryptography: public key encrypts, private key decrypts (e.g., RSA, ECC). Enables secure communication, digital signatures. Symmetric uses same key for both. [[CERT-In Guidelines]]
mRNA vaccines work by delivering genetic instructions for cells to produce a viral ________ protein.
- Envelope
- Spike
- Capsid
- Matrix
Answer: Spike
mRNA vaccines (e.g., COVID-19) encode the spike protein of SARS-CoV-2. Cells produce it, triggering immune response without live virus. Platform enables rapid vaccine development. [[ICMR, MoHFW Guidelines]]