Science & Technology - Biotechnology

Science and Technology - Biotechnology — Previous Year Questions (PYQs)

Figure 1: Biotechnology concepts frequently tested in UPSC examinations.

1. Introduction — Biotechnology Terms in News

• Biotechnology is a dynamic field with rapid advancements, frequently featuring in UPSC Prelims.
• This section covers key biotechnology terms asked in previous year questions.

KNOWLEDGE NUGGET

• Biotechnology: Application of biological systems to develop products and technologies
• Key Areas: Genetic engineering, molecular biology, bioinformatics, agricultural biotechnology, medical biotechnology

2. Biotechnology — Previous Year Questions

2023 — AERIAL METAGENOMICS

• Metagenomics (Environmental and Community Genomics): Involves the study of microorganisms through the direct extraction and analysis of DNA from their collective environment.
• Process: Isolating environmental DNA (e-DNA), inserting it into vectors, and then into host bacteria for screening.

2023 — ENVIRONMENTAL DNA (e-DNA)

• Refers to the DNA shed by animals through their breath, saliva, fur or feces into the environment.
• Facilitates comprehensive examination of an entire habitat and has been effective in identifying and monitoring terrestrial animals.

2023 — MICROSATELLITE DNA (Short Tandem Repeats — STRs)

• Short DNA sequences, typically one to six base pairs long, repeated in succession at specific locations in the genome.
• Typically non-coding and used as polymorphic markers for studying inheritance patterns or for creating a DNA fingerprint from crime scene samples.

2022 — BIOROCK TECHNOLOGY (Seacrete or Seament)

• Involves the use of low voltage electrical currents in seawater to precipitate dissolved minerals onto structures.
• Results in the formation of a white limestone (calcium carbonate) coating, akin to natural coral reefs and tropical white sand beaches.

2022 — DNA BARCODING

• Identification of species through a characteristic short DNA sequence in their genome by comparing individual sequences with a reference library.
• Useful for food authentication and prevalent in fish species identification.

2022 — BIOFILM

• A resistant layer of microorganisms, such as bacteria, that adhere to various surfaces, including medical devices, metals, plastics, and organic materials.
• Often enclosed in a self-produced extracellular polymeric substance (EPS), enabling attachment to virtually any surface.

2021 — MITOCHONDRIAL REPLACEMENT THERAPY (MRT)

• A new form of reproductive in-vitro fertilization (IVF) which works on the principle of replacing a woman's abnormal mitochondrial DNA (mt-DNA) with the donor's healthy one.
• Process: Nuclear genetic material is removed from eggs and transferred into donated eggs which have had their nuclear genetic material removed. The eggs are then fertilized with sperm to create embryos.

2021 — BOLLGARD I TECHNOLOGY

• Introduced in India in 2002, was the country's first approved Biotech Crop Technology.
• Utilizes a single-gene from Bacillus thuringiensis (Bt) for protection against the American Bollworm.

2021 — BOLLGARD II TECHNOLOGY

• Advanced in 2006 with double-gene technology (Cry1Ac and Cry2Ab).
• Offers enhanced defense against bollworms and Spodoptera caterpillars, leading to improved yield, reduced pesticide use, and increased boll retention.

2021 — CLONAL PROPAGATION

• A method of plant reproduction that involves creating new plants from the tissues, cells, or genetic material of a single parent plant.
• Bypasses sexual reproduction, ensuring progeny is genetically identical to the parent.
• Application: Horticulture and agriculture for rapid multiplication of plants with desirable traits.

2021 — GENETICALLY MODIFIED (GM) CROP

• Plants whose DNA has been altered using genetic engineering techniques.
• Involves insertion or deletion of genes to bestow new traits or enhance existing ones, such as resistance to pests, diseases, environmental conditions, and improved nutritional value.

2021 — PLANT GROWTH SUBSTANCES (Phytohormones)

• Natural compounds that regulate plant growth and development.
• Influence key processes such as cell division, flowering, root and shoot growth, and adaptation to environmental stresses.
• Examples: Auxins, Gibberellins, Cytokinins, Ethylene, and Abscisic acid.

2020 — PRONUCLEAR TRANSFER TECHNOLOGY

• Involves fertilization of eggs with sperm in a lab to create embryos.
• The nuclear genetic material within each embryo is then transferred into embryos created using donated eggs and sperm from the sperm provider.
• Three-parent babies are created through early pronuclear transfer to prevent passing on mitochondrial diseases from mother to child.

2019/20 — GENE SILENCING THERAPY (Gene Knockdown Technology)

• Leverages the body's inherent mechanisms to suppress or "silence" specific genes responsible for certain diseases or functions.
• Involves temporarily blocking the expression of a gene, preventing it from producing a protein that could lead to unwanted effects.
• Example: RNA interference (RNAi).

2019 — RNA INTERFERENCE (RNAi) TECHNOLOGY

• A gene-silencing technology that inhibits protein synthesis in target cells using double-stranded RNA.
• Used in functional genomics (systematic analysis of loss-of-function phenotypes induced by RNAi triggers) and developing therapies for viral infections, dominant disorders, neurological disorders, and many types of cancers.

2019 — HORMONE REPLACEMENT THERAPIES

• Treatment with hormones to replace natural hormones when the body does not make enough of the desired hormone.
• Example: Thyroid hormone given when the thyroid gland does not make enough.

2019 — SURFACE PLASMON RESONANCE

• Biosensors used in the direct and indirect detection of pathogenic microorganisms.

2019 — GLYPHOSATE

• The most widely used herbicide with genetically modified crops.
• Inactivates a key enzyme involved in amino acid synthesis in all green plants; effective broad-spectrum herbicide against nearly all weeds.
• Considered less toxic and less persistent than traditional herbicides, with fewer health risks for humans.

2017 — SOMATIC CELL NUCLEAR TRANSFER (SCNT)

• A cloning technique where a somatic (body) cell's nucleus is transferred into an enucleated egg (an egg that has had its own nucleus removed).
• Allows the egg to develop into an embryo, mimicking natural fertilization without using sperm.
• Can produce totipotent embryonic stem cells for research and therapeutic purposes; also used for reproductive cloning in animals.

2017 — BIOLARVICIDES

• Biocontrol agents derived from natural or genetically engineered microorganisms (bacteria, fungi, or viruses) that specifically target the larval life stage of an insect (mostly mosquito).
• Environmentally friendly alternative to chemical pesticides, controlling mosquito populations without harming non-target species or ecosystems.

2017 — REPRODUCTIVE CLONING

• A process used to generate an organism that has the same nuclear DNA as another currently or previously existing organism.
• Carried out through the technique known as Somatic Cell Nuclear Transfer (SCNT).

2017 — GENOME SEQUENCING

• The process of deciphering the order of base pairs to decode the genetic fingerprint of a human.
• DNA bases: Adenine (A), Cytosine (C), Guanine (G), and Thymine (T).
• Methods:
  • Clone-by-Clone: Sequencing the genome and inserting parts into bacteria to produce clones.
  • Whole-Genome Shotgun: Breaks DNA into small pieces for sequencing and clones them into batches for growth and subsequent sequencing.

2016 — TRANSCRIPTOME

• Refers to the full range of messenger RNA (mRNA) molecules expressed from an organism's genes.
• Refers to the set of all RNA molecules from protein coding genes to noncoding RNA, including rRNA, tRNA, lncRNA, pre-mRNA, and others.

2016 — GENETIC MUTATIONS

• A change in the DNA sequence within an organism's genome.
• Can occur due to errors during DNA replication or as a result of environmental factors.
• Can lead to changes in physical traits or affect ability to survive and reproduce, playing a crucial role in evolution and genetic diversity.

2013 — MYCORRHIZAL BIOTECHNOLOGY

• Involves the application of mycorrhizal fungi to enhance plant growth, health, and soil fertility.
• Pivotal in sustainable agriculture, reforestation, and environmental restoration.
• Mycorrhizae are symbiotic associations between plant roots and certain soil fungi which play a key role in nutrient cycling and protect plants against environmental and cultural stress.

2013 — RECOMBINANT DNA TECHNOLOGY (Genetic Engineering)

• Involves the application of mycorrhizal fungi to enhance plant growth, health, and soil fertility.
• This technology is pivotal in sustainable agriculture, reforestation, and environmental restoration, contributing significantly to ecological balance and conservation efforts.

2012 — BT BRINJAL

• A transgenic brinjal created by inserting a gene cry1Ac from the soil bacterium Bacillus thuringiensis into Brinjal.
• Gives resistance against insects such as the Brinjal Fruit and Shoot Borer.

2012 — BIOPESTICIDES

• A type of pesticides derived from natural materials such as animals, plants, bacteria, and certain minerals.
• Less toxic than conventional pesticides and affect only the target pests and closely related organisms.

2012 — ANTIOXIDANTS

• Molecules that combat oxidative stress by neutralizing free radicals (unstable atoms that can damage cells) that contribute to aging and diseases.
• Play a crucial role in maintaining health by preventing cell damage; found in various foods, including fruits and vegetables.

3. Important Terms in News

BIODEGRADABLE PLASTICS

• A novel approach to ensure that plastics that escape refuse streams are processed efficiently and broken down.
• Plastics produced with this method have a predetermined period during which they mimic traditional plastics in appearance and quality.

CELL FREE DNA (cfDNA)

• Tiny fragments of genetic material released into the bloodstream or other bodily fluids from dying cells.
• These fragments of DNA are not enclosed within cells, hence the term "cell-free."
• Often used for non-invasive medical diagnostics (e.g., cancer detection).

CRISPR/Cas9 SYSTEM

• CRISPR stands for "Clustered Regularly Interspaced Short Palindromic Repeats".
• A gene editing technology that allows scientists to precisely modify DNA within living organisms.
• Cas9: An enzyme that acts as molecular scissors, guided by RNA molecules synthesized to match a specific DNA sequence.

EPIGENETICS

• The study of how human behaviors and environment can cause changes that affect one's genetic functions.
• Epigenetic epidemiology: The study of how epigenetic changes, such as DNA methylation, histone modification etc., contribute to the occurrence and distribution of diseases across populations.

GENE DRIVE

• A method that enhances the inheritance of a modified or preferred trait in a specific species.
• The fundamental idea behind genetic manipulation of mosquitoes is to systematically control their populations by interfering with their reproduction.

GERMLINE GENE THERAPY

• DNA is inserted into the reproductive cells (eggs or sperm) in the human body.
• It will correct the genetic variants of the reproductive cells of an individual, and this would be passed down to future generations.
• Germ line refers to the sex cells (eggs and sperm) that sexually reproduce organisms use to pass on their genomes from one generation to the next.

HUMAN EARLY EMBRYONIC CELLS (HEC)

• Early human embryonic cells have an inner cell mass of pluripotent cells that can transform into all types of cells in the human body. These cells perish early in development.
• These cells produce transposons or 'jumping genes' which can insert themselves within the genome, possibly causing DNA damage and resulting in cell death.

NON-CODING DNA — REPETITIVE DNA

• Refers to DNA sequences repeated multiple times in an organism's genome.
• Many repetitive sequences do not have a known function and are sometimes referred to as "junk DNA".
• Satellite DNA: The simplest form of repetitive DNA, which consists of DNA blocks in tandem repeats.
• Application: Researchers use satellite DNA as a genomic "fingerprint" to match crime scene samples and track ancestry.

PANTRANSCRIPTOME

• A combination of a transcriptome and a pangenome — a reference that contains genetic material from a cohort of diverse individuals rather than just a single linear strand.
• Pangenome: The entire gene set of all strains in a species divided into three parts: core genome, dispensable genome, and unique genes.
• A single reference genome isn't always reliable due to intra-species variations.
• Pan-transcriptome studies all RNA molecules, aiding in analyzing complex genomes and inter-species differences.

SINGLE NUCLEOTIDE POLYMORPHISM (SNP)

• A DNA sequence variation occurring when a single nucleotide (A, C, G, or T) differs between members of a species or paired chromosomes in an individual.
• Can act as biological markers, helping scientists locate genes associated with diseases.

STEM CELLS

• Special human cells that have the ability to differentiate into specific cell types (muscle cells to brain cells).
• Two defining characteristics: Perpetual self-renewal and ability to differentiate into a specialized adult cell type.
• Major classes:
  • Pluripotent: Can become any cell in the adult body.
  • Multipotent: Restricted to becoming a more limited population of cells.

STEM CELL THERAPY

• A novel therapeutic approach that utilizes the unique properties of stem cells, including self-renewal and differentiation, to regenerate damaged cells and tissues or replace these cells with new, healthy, and fully functional cells.
• Sources:
  • Autologous: Self-to-self therapy using the patient's own cells.
  • Allogeneic: Uses cells from a healthy donor for the treatment.

4. Summary: Biotechnology PYQs at a Glance

Year	Term	Key Description
2023	Aerial Metagenomics	Study of microorganisms through direct extraction of DNA from environment
2023	Environmental DNA (e-DNA)	DNA shed by animals through breath, saliva, fur, feces
2023	Microsatellite DNA (STRs)	Short DNA sequences (1-6 bp) repeated in succession; used for DNA fingerprinting
2022	Biorock Technology	Low voltage electrical currents in seawater to precipitate minerals (limestone coating)
2022	DNA Barcoding	Identification of species through short DNA sequence; useful for food authentication
2022	Biofilm	Resistant layer of microorganisms enclosed in EPS; adheres to surfaces
2021	Mitochondrial Replacement Therapy (MRT)	Replacing abnormal mt-DNA with donor's healthy one; IVF technique
2021	Bollgard I & II	Bt cotton with single (2002) and double-gene (2006) technology
2021	Clonal Propagation	Asexual reproduction creating genetically identical plants
2020	Pronuclear Transfer Technology	Three-parent babies; prevents mitochondrial diseases
2019	RNA Interference (RNAi)	Gene-silencing technology using double-stranded RNA
2017	SCNT	Somatic cell nucleus into enucleated egg; cloning technique
2017	Genome Sequencing	Deciphering order of base pairs; clone-by-clone & shotgun methods
2016	Transcriptome	Full range of RNA molecules expressed from an organism's genes
2013	Mycorrhizal Biotechnology	Application of mycorrhizal fungi for plant growth, soil fertility
2012	Bt Brinjal	cry1Ac gene from Bt inserted into brinjal; resistance to Fruit and Shoot Borer

Key Takeaways for UPSC

• CRISPR/Cas9: Gene editing technology — molecular scissors guided by RNA
• RNAi: Gene silencing using double-stranded RNA
• SCNT: Somatic Cell Nuclear Transfer — cloning technique
• cfDNA: Cell-free DNA — non-invasive diagnostics (cancer detection)
• e-DNA: Environmental DNA — shed by animals into environment
• Biorock: Low voltage currents in seawater — limestone coating for coral reefs
• Mitochondrial Replacement Therapy: Three-parent babies — prevents mitochondrial diseases
• Bt Technology: Bollgard I (single gene), Bollgard II (double gene — Cry1Ac and Cry2Ab)
• Glyphosate: Broad-spectrum herbicide — less toxic than traditional herbicides
• Stem Cell Therapy: Autologous (self) or Allogeneic (donor)

High-Yield Interactive UPSC Quiz (Biotechnology)

Q1. CRISPR technology is used for:

Correct Answer: B. CRISPR/Cas9 is a gene editing technology that allows scientists to precisely modify DNA within living organisms. Cas9 acts as molecular scissors guided by RNA molecules.

Q2. RNA interference (RNAi) is a technology used for:

Correct Answer: B. RNA interference (RNAi) is a gene-silencing technology that inhibits protein synthesis in target cells using double-stranded RNA.

Q3. Somatic Cell Nuclear Transfer (SCNT) is used for:

Correct Answer: C. SCNT is a cloning technique where a somatic cell's nucleus is transferred into an enucleated egg, leading to the birth of a genetically identical individual.

Q4. Bollgard I technology was introduced in India in which year?

Correct Answer: B. Bollgard I, introduced in India in 2002, was the country's first approved Biotech Crop Technology, utilizing a single-gene from Bacillus thuringiensis (Bt).

Q5. Mitochondrial Replacement Therapy (MRT) is used to prevent:

Correct Answer: B. Mitochondrial Replacement Therapy (MRT) works on the principle of replacing a woman's abnormal mitochondrial DNA (mt-DNA) with the donor's healthy one to prevent mitochondrial diseases.

Q6. Environmental DNA (e-DNA) refers to:

Correct Answer: B. Environmental DNA (e-DNA) refers to the DNA shed by animals through their breath, saliva, fur or feces into the environment.

Q7. Biorock Technology involves the use of:

Correct Answer: B. Biorock Technology involves the use of low voltage electrical currents in seawater to precipitate dissolved minerals onto structures, forming a white limestone coating.

Q8. Cell Free DNA (cfDNA) is commonly used for:

Correct Answer: B. Cell Free DNA (cfDNA) refers to tiny fragments of genetic material released into the bloodstream from dying cells. It is often used for non-invasive medical diagnostics, e.g., cancer detection.

Q9. Which of the following is NOT a phytohormone?

Correct Answer: C. Insulin is a hormone produced by the pancreas in animals, not a plant growth substance (phytohormone). Phytohormones include Auxins, Gibberellins, Cytokinins, Ethylene, and Abscisic acid.

Q10. Which technique creates "three-parent babies" to prevent mitochondrial diseases?

Correct Answer: C. Three-parent babies are created through a technique called early pronuclear transfer and is used to prevent passing on of mitochondrial diseases from a mother to her child.