Biotechnology — Set 1

Correct Answer: A. Restriction Enzymes

• **Restriction Enzymes** = Restriction enzymes cut DNA at specific nucleotide sequences, acting like molecular scissors. • **Molecular scissors** — They are essential for isolating specific genes during cloning and were originally discovered in bacteria as a defense against viruses. • 💡 Wrong-option analysis: DNA Ligase: joins DNA fragments; Polymerase: synthesizes DNA or RNA; Helicase: unwinds DNA double helix.

Correct Answer: D. To provide optimal conditions for microbial growth

• **Bioreactor** = Bioreactors maintain controlled environments for the large-scale growth of microorganisms or cells. • **Optimal conditions** — They regulate factors like temperature, pH, and oxygen to maximize product yield, such as vaccines and organic acids. • 💡 Wrong-option analysis: To store chemicals: this is a general function, not the primary purpose of a bioreactor; To freeze biological samples: this is done for cryopreservation, not in a bioreactor; To sequence DNA: this is done using DNA sequencing technologies.

Correct Answer: A. Bioremediation

• **Bioremediation** = Bioremediation uses microorganisms or plants to break down or absorb environmental contaminants. • **Eco-friendly method** — It is an eco-friendly method for treating oil spills and heavy metal toxicity, relying on natural metabolic pathways. • 💡 Wrong-option analysis: Biofortification: enhances nutritional value of crops; Bioprospecting: explores biodiversity for valuable genetic resources; Biopiracy: refers to the unethical appropriation of biological resources or traditional knowledge.

Correct Answer: A. Enhancing the nutritional value of crops

• **Biofortification** = Biofortification involves breeding crops to increase their content of essential vitamins and minerals. • **'Hidden hunger'** — It helps combat 'hidden hunger' in populations dependent on staple foods, with Golden Rice (enriched with Vitamin A) being a famous example. • 💡 Wrong-option analysis: Increasing crop yield: primarily aims at quantity, not quality; Developing pest resistance: achieved through genetic modification like Bt crops; Improving shelf life: often done through genetic engineering or post-harvest treatments.

Correct Answer: D. Red

• **Red biotechnology** = Red biotechnology focuses on the development of medicines, vaccines, and diagnostic tools. • **Advanced therapies** — It includes advanced therapies like stem cell research and gene therapy, contributing to human health applications. • 💡 Wrong-option analysis: Green: associated with agriculture; Blue: related to marine and aquatic biotechnology; White: refers to industrial biotechnology.

Correct Answer: A. Clustered Regularly Interspaced Short Palindromic Repeats

• **Clustered Regularly Interspaced Short Palindromic Repeats** = CRISPR refers to specific sequences in DNA that act as a revolutionary gene-editing system. • **High precision** — This technology allows scientists to modify DNA sequences and gene function with high precision, adapted from bacteria's natural defense mechanisms. • 💡 Wrong-option analysis: Cellular Recognition Involving Short Protein Receptors: not the full form of CRISPR; Chromosomal Repair in Single Protein Regions: not the full form of CRISPR; Clustered Ribosomal Interspaced Systemic Protein RNA: not the full form of CRISPR.

Correct Answer: D. Variable Number Tandem Repeats (VNTRs)

• **Variable Number Tandem Repeats (VNTRs)** = VNTRs are non-coding DNA sequences that vary significantly in length between individuals. • **1984** — This technique, developed by Sir Alec Jeffreys in **1984**, provides a unique genetic pattern used for forensic and paternity testing. • 💡 Wrong-option analysis: Coding regions: these are genes that code for proteins and are largely conserved; Exons only: exons are part of coding regions and do not show enough variability; Ribosomal RNA: crucial for protein synthesis but highly conserved and not used for individual identification.

Correct Answer: A. DNA Ligase

• **DNA Ligase** = DNA ligase facilitates the joining of DNA strands by catalyzing the formation of a phosphodiester bond. • **Recombinant DNA** — It is a critical tool for creating recombinant DNA molecules in labs and also plays a vital role in natural DNA replication and repair. • 💡 Wrong-option analysis: Amylase: breaks down starches; Lipase: breaks down fats; Exonuclease: cleaves nucleotides from the end of a polynucleotide chain.

Correct Answer: D. Bollworms

• **Bollworms** = Bt Cotton is genetically modified to be resistant to bollworms, a major agricultural pest. • **Reduced pesticide use** — It contains genes from Bacillus thuringiensis that produce insecticidal proteins, reducing the need for chemical pesticides and becoming a widely adopted transgenic crop. • 💡 Wrong-option analysis: Drought: requires different genetic modifications for water stress tolerance; Herbicides: resistance is developed against specific herbicides (e.g., Roundup Ready crops); Fungal infections: requires different genes for disease resistance.

Correct Answer: A. Insulin

• **Insulin** = Synthetic human insulin, known as Humulin, was the first human hormone produced by recombinant DNA technology. • **1982** — Humulin was approved for medical use in **1982**, a landmark achievement that replaced insulin previously extracted from animal pancreases. • 💡 Wrong-option analysis: Thyroxine: a thyroid hormone; Estrogen: a female sex hormone; Adrenaline: a stress hormone; none of these were the first recombinant human hormone.