Explanation:

• Microbial remediation, also known as bioremediation, is the process of using microorganisms to degrade, detoxify, or transform pollutants in the environment.
• Bacteria, fungi, and algae are all used in microbial remediation for their ability to degrade various pollutants. Viruses are not typically used in bioremediation processes.
• Bacteria: Many bacterial species are known to metabolize pollutants and are widely used in bioremediation. For example, species like Arthrobacter, Pseudomonas, Burkholderia, and Bacillus are utilized for their ability to absorb and detoxify heavy metals.
• Fungi: Fungi such as Penicillium and Aspergillus are also employed in bioremediation due to their capacity to absorb and concentrate toxic metals from aqueous solutions.
• Algae: Algae can absorb heavy metals and other pollutants, playing a significant role in the bioremediation of water bodies.

Explanation:

• Bioreactors use engineered vessels to treat contaminated materials under controlled conditions, allowing for precise control of environmental factors to optimize microbial degradation.

Explanation:

• Bioaugmentation (1-D): Introduction of specific microorganisms to a contaminated site.
• Bioventing (2-B): Injection of air into the soil to stimulate microbial activity.
• Biosparging (3-C): Injection of air and nutrients into groundwater to enhance microbial degradation.
• Phytoremediation (4-A): Use of plants to remove or neutralize contaminants.

Explanation:

The correct sequence of steps in the SCNT process is as follows:

• Extraction of the nucleus from a somatic cell (2): The first step involves extracting the nucleus from a somatic cell, which contains the genetic material to be cloned.
• Enucleation of the egg cell (3): The second step is the removal of the nucleus from an egg cell, creating an enucleated egg cell.
• Nuclear transfer (4): The third step involves transferring the somatic cell nucleus into the enucleated egg cell.
• Implantation of the cloned embryo into a surrogate mother (1): The final step is the implantation of the resulting cloned embryo into a surrogate mother for further development.

Explanation:

• Reproductive cloning → Produces an entire living organism genetically identical to the donor. It is different from therapeutic cloning, which focuses on generating stem cells for medical purposes.
• Statement 1: Producing genetically identical animals → Correct
  • Example: The cloning of Dolly the sheep (1996).
• Statement 2: Generating stem cells for medical treatments → Not correct
  • This falls under therapeutic cloning, not reproductive cloning.
• Statement 3: Cloning endangered species → Correct
  • Reproductive cloning has been proposed to help conserve or revive endangered species.
• Statement 4: Improving crop varieties → Correct
  • Reproductive cloning principles can be extended in plant biotechnology for uniform, high-yield crop varieties.

👉 Hence, 1, 3, and 4 are correct.

Explanations

• Collagen → Holds tissues together; found in skin, bones, cartilage.
• Trypsin → An enzyme that helps digest proteins in food.
• Insulin → A hormone that regulates blood sugar level.
• Antibodies → Special proteins that defend the body against germs and viruses.
• Receptors → Proteins that help us sense signals like smell, taste, hormones.
• GLUT-4 → A protein that transports glucose into body cells.

Explanation:

• Agricultural waste: This encompasses a variety of organic materials produced as byproducts of agricultural activities.
• Manure: Animal manure is a primary substrate for biogas generation due to its high organic content and availability
• Sugarcane: While not commonly cited as a direct source for biogas, sugarcane can be involved in the production of biogas through its byproducts, like bagasse.
• Food waste: Organic food waste is another significant contributor to biogas production due to its high biodegradability and methane potential.

Explanation:

• Neem oil is derived from the neem tree and is known for its pest-repelling properties, making it a biochemical pesticide.
• Bacillus thuringiensis is a bacterium that acts as a microbial pesticide, which is often included in the broader category of biopesticides. However, it is not a biochemical pesticide because it does not function through non-toxic mechanisms; instead, it produces toxins that kill certain insects.
• Pheromones are biochemicals used by insects to communicate. When used as pesticides, they disrupt the pest’s behavior, such as mating, which is a non-toxic mechanism, thus qualifying as biochemical pesticides1.
• Neem Coated Urea is not a pesticide. It is a fertilizer that is coated with neem oil to slow down the release of nitrogen, making it more efficient and lessening the environmental impact. While neem oil is a biochemical pesticide, the urea itself is not, and the primary purpose here is not pest control.

Explanation:

• Rhizobium is a well-known nitrogen-fixing bacterium that forms symbiotic relationships with leguminous plants, fixing atmospheric nitrogen into a form that plants can use.
• Azotobacter is a free-living nitrogen fixer, meaning it does not require a symbiotic relationship with plants to fix nitrogen. It is commonly used as a bio-fertilizer for various crops.
• Bacillus mucilaginosus is known for its ability to solubilize phosphate but is not typically recognized for nitrogen fixation.
• Azospirillum is an associative nitrogen fixer, which means it lives in close association with plants and can fix atmospheric nitrogen.

Explanation:

• Statement 1 is correct. Gene therapy indeed focuses on the genetic modification of cells to produce a therapeutic effect or to treat diseases by repairing or reconstructing defective genetic material.
• Statement 2 is correct. The concept of gene therapy includes fixing a genetic problem at its source by delivering a copy of a gene without the deleterious mutation, which can then produce a functional protein.
• Statement 3 is correct. The introduction of CRISPR gene editing has opened new doors for gene therapy, allowing the correction of specific genetic defects rather than just replacing the gene, enhancing the scope of gene therapy applications.
• Gene therapy, especially with advancements like CRISPR, is opening new horizons in medical science, similar to how biotechnology and bioinformatics are transforming fields like genetic sequencing and data analysis.

Explanation:

1. Restriction Enzyme Digestion (B): Cuts DNA at specific sequences.

2. Ligase Reaction (D): Joins DNA fragments.

3. Transformation (C): Introduces recombinant DNA into a host cell.

4. Polymerase Chain Reaction (PCR) (A): Amplifies DNA fragments.

Explanation:

All three statements are correct. Gene cloning is used in:

• The production of insulin, by cloning the human insulin gene and inserting it into bacteria.
• The development of genetically modified crops, by cloning genes that confer desirable traits and introducing them into plants.
• The creation of animal models for research, by cloning genes of interest and inserting them into animals to study gene function and disease mechanisms.

Explanation:

• Statement 1 is correct. DNA ligase acts as a molecular stitcher, joining DNA fragments together.
• Statement 2 is incorrect. DNA ligase joins DNA fragments by forming an inter-nucleotide ester bond, not hydrogen bonds.
• Statement 3 is correct. DNA ligase is essential for DNA replication, repair, and recombination.

Explanation:

• Statement 1 is correct. Restriction enzymes are proteins produced by bacteria that cleave DNA at specific sites, serving as a defense mechanism against foreign DNA, such as that from bacteriophages.
• Statement 2 is correct. The first restriction endonuclease discovered was Hind II, which cleaves DNA at specific sites, making it a critical tool in genetic engineering and molecular biology.
• Statement 3 is correct. Restriction enzymes prevent the replication of phage DNA by cutting it into multiple pieces, thereby restricting the growth and propagation of the bacteriophage within the bacterial cell.

Explanation:

1. Western blotting – Detection of RNA → Incorrect

• Western blotting is used for the detection of proteins.
• Principle: Proteins are separated by SDS-PAGE (gel electrophoresis), then transferred onto a membrane and detected using specific antibodies.
• Application: Used in diagnostics (e.g., confirmation of HIV, prion diseases), research (protein expression studies).
• Hence, RNA detection is wrong here.

2. Northern blotting – Identification of isolated proteins → Incorrect

• Northern blotting is specifically used for the detection of RNA (mRNA, rRNA, etc.).
• Principle: RNA molecules are separated by electrophoresis, transferred to a membrane, and hybridized with complementary DNA or RNA probes.
• Application: Studying gene expression by analyzing mRNA levels.
• So, associating it with proteins is incorrect.

3. Southern blotting – DNA fingerprinting → Correct

• Southern blotting is used for DNA analysis.
• Principle: DNA is fragmented by restriction enzymes, separated by electrophoresis, transferred to a membrane, and hybridized with a labeled probe.
• Application:
  • DNA fingerprinting
  • Gene mapping
  • Detecting mutations, insertions, or deletions
• Hence, this pair is correct.

Mnemonic to Remember:

• S → Southern → DNA (Think “S” for Sequence of DNA)
• N → Northern → RNA (Think “N” for nucleic acids in RNA)
• W → Western → Proteins (Think “W” for Weight of proteins)

Explanation:

1. Isolation of Genetic Material: This is the first step where the DNA containing the gene of interest is isolated from the donor organism.

2. Cutting of DNA at Specific Locations: The isolated DNA is cut into fragments using restriction enzymes.

3. Amplification of Gene of Interest using PCR: The specific gene of interest is amplified using Polymerase Chain Reaction (PCR) to produce multiple copies.

4. Introduction of the Recombinant DNA into the Host Cell/Organism: The recombinant DNA is introduced into a host cell or organism to replicate and express the gene of interest.

5. Obtaining the Foreign Gene Product: The host organism produces the foreign gene product, which is then extracted and purified.

6. Downstream Processing: The final step involves processing the gene product for commercial or therapeutic use.

Explanation:

• All three statements are correct. Cloning vectors are DNA molecules that carry the gene of interest into the host cell, they can replicate independently inside the host cell, and common examples include plasmids, bacteriophages, and cosmids.

Explanation:

• Statement 1 is correct. PCR is a procedure that replicates DNA without requiring a living cell, using a solution containing DNA, Taq polymerase, primers, and dNTPs.
• Statement 2 is correct. PCR involves cycles of heating and cooling, and each cycle doubles the number of DNA copies, allowing for the amplification of specific DNA sequences.

Explanation:

• 1. Azotobacter – Yes ✔️
  • A free-living nitrogen-fixing bacterium found in soil.
  • Used as a biofertilizer for crops like wheat, maize, cotton, mustard, etc.
  • Improves nitrogen content in soil and enhances crop yield.
• 2. Mycorrhiza – Yes ✔️
  • Symbiotic association between fungi and plant roots.
  • Helps in phosphorus absorption, water uptake, and provides resistance against soil-borne pathogens.
  • Example: Glomus species used as biofertilizer.
• 3. Spirogyra – No ❌
  • It is a green alga, commonly found in freshwater.
  • Not used as a biofertilizer.
  • Instead, blue-green algae (like Anabaena, Nostoc) are used in paddy fields.
• 4. Frankia – Yes ✔️
  • A filamentous bacterium that forms symbiotic associations with actinorhizal plants (e.g., Alnus).
  • Fixes atmospheric nitrogen → used as biofertilizer.
• 5. Agaricus – No ❌
  • Common edible mushroom.
  • Cultivated for food, not for biofertilizer use

Explanation:

• Mitochondrial Replacement Therapy (MRT):
  • Mitochondria have their own DNA (mtDNA), separate from nuclear DNA.
  • Mutations in mtDNA can cause mitochondrial diseases, which are transmitted maternally.
  • MRT is an advanced reproductive technique that replaces defective mitochondria in an egg with healthy mitochondria from a donor.
  • This can be done before or after in vitro fertilization (IVF), hence statement 1 is correct.
• Maternal Inheritance of Mitochondria:
  • Sperm mitochondria are usually destroyed after fertilization.
  • Thus, a child’s mitochondria are inherited exclusively from the mother.
  • This means mitochondrial diseases, if present, are passed down only through the maternal line.
  • Hence, statement 2 is also correct.

👉 Therefore, both statements are correct.

Explanations

• Bt Cotton → Pest-resistant (B)
  • Genetically modified with Bacillus thuringiensis gene.
  • Provides resistance against bollworm pests.
• Golden Rice → Contains Vitamin A (A)
  • Biofortified with beta-carotene (precursor of Vitamin A).
  • Helps combat Vitamin A deficiency, especially in developing countries.
• Sub-1 Rice → Resistant to Flooding (C)
  • Developed with Submergence-1 (Sub-1) gene.
  • Can survive underwater for up to 2 weeks during floods.
• Dhara Mustard Hybrid (DMH-11) → Approved for environmental release (D)
  • India’s first GM food crop to get approval (2022).
  • Genetically modified mustard hybrid for higher yields.

Explanation:

• Statement 1 → Correct: Genome sequencing allows scientists to identify genetic markers linked with desirable traits like drought tolerance and disease resistance. This helps in crop improvement programs.
• Statement 2 → Correct: By identifying specific genes quickly, genome sequencing reduces the breeding cycle, thus decreasing the time needed to develop new, improved crop varieties.
• Statement 3 → Correct: Genome sequencing enables study of host-pathogen interactions at the molecular level, which helps in developing resistant crops and better disease management strategies.

👉 Therefore, all three statements are correct.

Explanation:

• The transcriptome is the complete set of RNA transcripts (particularly mRNA molecules) produced by the genome under specific conditions in a cell or tissue.
• It reflects which genes are actively expressed at a given time, unlike the genome, which is constant.
• Studying the transcriptome helps scientists understand gene expression patterns, disease mechanisms, and cellular responses.
• It is a key area in bioinformatics, genomics, and systems biology.
• Other options:
  • A → enzymes like CRISPR-Cas9 are used in genome editing, not transcriptome.
  • C → relates to gene expression studies but not the definition of transcriptome.
  • D → mutation is unrelated to the transcriptome.

Explanation:

• Statement 1: Assess the age → Not correct
  • DNA barcoding cannot be used to determine the age of an organism. Age determination usually requires dendrochronology (for trees), radiocarbon dating, or physiological/structural studies.
• Statement 2: Distinguish among species that look alike → Correct
  • DNA barcoding uses a short, standardized region of the genome (often mitochondrial COI gene in animals, rbcL/matK in plants) to identify and differentiate species, especially those that are morphologically similar.
• Statement 3: Identify undesirable materials in processed foods → Correct
  • DNA barcoding can detect adulteration or contamination in food (e.g., mixing of cheaper plant/animal species into processed food products).

👉 Therefore, the correct answer is 2 and 3 only.

Explanation:

• SAATVIK (NC 9) is a newly developed chickpea (gram) variety.
• It has been notified and approved by the Central Sub-Committee on Crop Standards.

Key Features of SAATVIK (NC 9):

• Climate Smart: Developed to adapt to changing climate conditions.
• Drought Tolerant: Performs better under water-stressed conditions, suitable for semi-arid regions.
• High Yielding: Offers enhanced productivity compared to traditional chickpea varieties.
• Resilient Agriculture: Supports India’s goals of sustainable farming and nutritional security.

Why Important?

• India is the largest producer and consumer of chickpea (gram).
• Drought is a major constraint in pulse-growing regions, reducing yields significantly.
• Introducing such varieties ensures:
  • Higher pulse availability domestically → reducing import dependency.
  • Strengthening of food and nutritional security.
  • Alignment with India’s National Food Security Mission (NFSM-Pulses).

Other Options (Why Incorrect?):

• B (Wheat variety): Flood-resistant wheat exists (HD 2967, DBW 187 etc.), but SAATVIK is not wheat.
• C (Rice variety): Short-duration rice varieties like Pusa Basmati 1509 are known, but SAATVIK is not rice.
• D (Maize variety): Hybrid maize with high protein (QPM) exists, but SAATVIK is not maize.

Explanation:

• Indian researchers have developed a stable fungal enzyme nano-formulation from Myrothecium verrucaria.
• Purpose: Eco-friendly biocontrol of powdery mildew disease in tomato and grape crops, which causes major yield losses.
• Significance:
  • Reduces dependency on chemical fungicides.
  • Promotes sustainable agriculture and aligns with the Integrated Pest Management (IPM) approach.
• Other options are incorrect:
  • A (Rhizobium) → used for nitrogen fixation in legumes, not mildew control.
  • C (Baculoviruses) → used as bio-pesticides, mainly against insect pests, not fungal diseases.
  • D (Trichoderma) → is a common biocontrol fungus, but the specific breakthrough here is with Myrothecium verrucaria.

Explanation:

• Nafithromycin is India’s first indigenous antibiotic to address the growing challenge of Antimicrobial Resistance (AMR).
• Developed with support from the Biotechnology Industry Research Assistance Council (BIRAC).
• Marketed by Wockhardt under the brand name Miqnaf.
• Significance:
  • First new antibiotic in its class in over 30 years.
  • Represents a major milestone in India’s efforts to combat drug-resistant bacterial infections.
  • Strengthens India’s contribution to the global fight against AMR.

Explanation:

• Mycorrhizae are symbiotic associations between fungi and plant roots. They are crucial in soil fertility, nutrient uptake, and ecological restoration.
• Statement 1 → Correct
  • Mycorrhiza increases the absorptive area of roots (via fungal hyphae), improving uptake of water and nutrients.
  • This helps plants resist drought stress.
• Statement 2 → Correct
  • Mycorrhiza improves plant tolerance to extreme soil conditions, including highly acidic or alkaline soils, making them suitable for rehabilitation of degraded lands.
• Statement 3 → Correct
  • Mycorrhizal fungi provide a protective shield around roots, enhancing resistance against soil-borne pathogens and disease infestation.

👉 Thus, all three statements are correct.

Explanation:

• Why Assertion is correct:
  • Bioplastics are derived from renewable biomass sources such as corn starch, sugarcane, cassava, or potato starch.
  • They can reduce dependence on fossil fuels and potentially lower greenhouse gas emissions compared to petroleum-based plastics.
  • Some bioplastics are designed to biodegrade under specific conditions, making them a greener alternative in waste management.
• Why Reason is wrong:
  • Not all bioplastics are universally biodegradable.
  • Some bioplastics, like PLA (Polylactic Acid), require industrial composting plants (high temperature and controlled microbes) for proper degradation.
  • Others may persist in landfills or marine environments, behaving similarly to conventional plastics.
  • Also, “bio-based” does not always mean “biodegradable.” For example, bio-PET (made partly from biomass) is chemically identical to normal PET and is not biodegradable.
• Conclusion:
  • While bioplastics are generally more environmentally friendly, it is incorrect to say they are entirely biodegradable under all conditions.
  • Thus, Assertion (A) is correct, but Reason (R) is wrong.

Explanation:

• Why Assertion (A) is correct:
  • CRISPR-Cas9 has emerged as a powerful gene-editing tool and is being applied in experimental therapies for human genetic disorders.
  • Examples include sickle-cell anemia, β-thalassemia, muscular dystrophy, and certain eye disorders (like Leber congenital amaurosis).
  • In these cases, scientists edit somatic cells (body cells), not germline cells, to correct defective genes and restore normal function.
• Why Reason (R) is wrong:
  • CRISPR does not require altering germline DNA to treat most genetic diseases.
  • Somatic cell therapy corrects the genetic error only in targeted tissues, and these changes are not passed on to future generations.
  • Germline editing (sperm, egg, embryo) would indeed make inherited diseases disappear across generations, but it is ethically controversial, largely banned/restricted, and considered unsafe due to risks of off-target mutations.
• Key point:
  • Current clinical applications of CRISPR focus on somatic editing for therapy.
  • Germline editing is still in the experimental/ethical debate stage, not an accepted treatment method.

Final Conclusion:

• CRISPR is already being used experimentally to treat human genetic disorders (Assertion correct).
• But it does not require germline DNA editing; instead, it targets somatic cells (Reason wrong).
• Hence, Answer: C (A is correct, but R is wrong).