Chapter 10: Biotechnology

Select the correct answer:

1. The use of living organisms or their processes and products for the welfare of mankind is called:

A) applied science

B) technology

C) biotechnology

D) genetic engineering

Answer: C) biotechnology

Explanation: Biotechnology is defined as the use of living organisms (such as bacteria, yeast, plants) or their components (enzymes, genes) to develop or make useful products for human welfare. It encompasses traditional processes like fermentation and modern techniques like genetic engineering.

2. Gene "cry" responsible for the pest resistance is obtained from a bacterium:

A) Bacillus thuringiensis

B) Bacillus aureus

C) E. coli

D) Pseudomonas

Answer: A) Bacillus thuringiensis

Explanation: The "cry" genes are isolated from the soil bacterium Bacillus thuringiensis (Bt). These genes code for crystal proteins (Cry proteins) that are toxic to specific insect larvae (e.g., bollworms). Crops like Bt cotton are genetically modified to carry these genes.

3. Genetically modified variety of sugarcane, which have both Cry1Ac + cry2Ab genes of bacteria is resistant against:

A) high temperature

B) drought

C) sugarcane top borer

D) pH changes

Answer: C) sugarcane top borer

Explanation: The Cry1Ac and Cry2Ab genes from Bacillus thuringiensis provide resistance against lepidopteran pests, specifically the sugarcane top borer, a major pest of sugarcane crops.

4. These are used in making yogurt:

A) bacteria

B) fungi

C) yeast

D) alga

Answer: A) bacteria

Explanation: Yogurt is produced by the fermentation of milk by specific bacteria, primarily Lactobacillus bulgaricus and Streptococcus thermophilus. These bacteria convert lactose (milk sugar) into lactic acid, which thickens the milk and gives yogurt its tangy taste.

5. Biological pest control:

A) is rapid control

B) is slow control

C) causes pollution

D) damage crops

Answer: B) is slow control

Explanation: Biological pest control involves using natural predators, parasites, or pathogens to control pest populations. It is slower-acting than chemical pesticides but is environmentally friendly, does not cause pollution, and does not damage crops.

6. HbA1c test measures the amount of blood glucose:

A) in plasma

B) in liver cells

C) attached to haemoglobin in RBCs

D) attached to muscle cells

Answer: C) attached to haemoglobin in RBCs

Explanation: The HbA1c test measures the percentage of glycated hemoglobin (hemoglobin with glucose attached) in the blood. Since red blood cells live for about 3 months, this test reflects the average blood glucose level over the past 2-3 months. It is used to diagnose and monitor diabetes.

7. A bacterium is considered genetically modified when it has:

A) a foreign gene

B) Many plasmids

C) A complete genome

D) Restriction endonucleases

Answer: A) a foreign gene

Explanation: A bacterium is considered genetically modified (transgenic) when a foreign gene (from another organism) has been introduced into its genome using recombinant DNA technology.

8. Interferons are special proteins produced by human cells that:

A) Reduce pain

B) Cause fever

C) Reduce the multiplication of viruses

D) Dissolve blood clots

Answer: C) Reduce the multiplication of viruses

Explanation: Interferons are proteins released by virus-infected cells. They bind to receptors on neighboring uninfected cells, inducing the production of antiviral proteins that inhibit viral replication, thus limiting the spread of the virus.

9. Microorganisms Anabaena azollae borne naturally in propagates in seawater containing crude oil?

A) an alkane-degrading marine bacterium

B) naturally propagates in freshwater

C) improve crop yield

D) causes cancer

Answer: B) naturally propagates in freshwater (Note: Anabaena azollae is a cyanobacterium that lives symbiotically in the leaves of the water fern Azolla. It is a freshwater organism, not a marine bacterium. It is used as a biofertilizer.)

1. What is meant by artificial prions. Give its role.

Answer: Artificial prions are synthetic or laboratory-generated misfolded proteins that mimic the structure and behavior of natural prions. Natural prions are infectious agents composed entirely of protein (PrP^Sc) that cause neurodegenerative diseases like Creutzfeldt-Jakob disease (CJD) and Bovine Spongiform Encephalopathy (BSE).

Role in Research: Artificial prions are used in research to study the mechanisms of protein misfolding, aggregation, and neurodegeneration. They help scientists understand how prions propagate and cause disease, aiding in the development of diagnostic tools and potential therapeutic strategies.

2. How biomarkers work in sugar control?

Answer: Biomarkers are measurable indicators of biological processes. In sugar control, the primary biomarker is HbA1c (glycated hemoglobin). It measures the average blood glucose level over the past 2-3 months. Since glucose attaches to hemoglobin in red blood cells, the level of HbA1c reflects long-term blood sugar control. Other biomarkers include fructosamine (reflects 2-3 week control) and fasting blood glucose. These biomarkers help doctors diagnose diabetes, monitor treatment effectiveness, and adjust medication.

3. How has genetic engineering improved the quality of agricultural yield?

Answer: Genetic engineering has improved agricultural yield by:

Pest Resistance: Bt crops (e.g., Bt cotton) produce toxins that kill specific pests, reducing crop losses. Herbicide Tolerance: Crops like Roundup Ready soybeans can survive herbicide application, allowing effective weed control. Disease Resistance: Crops engineered to resist viral, bacterial, and fungal diseases. Drought/Salinity Tolerance: Crops engineered to survive in harsh environmental conditions. Nutritional Enhancement: Biofortified crops like Golden Rice (rich in Vitamin A). Increased Yield: Higher productivity per acre.

4. Effective management and treatment of any type of cancer mainly depends upon which factors?

Answer: Effective management and treatment of cancer depends on:

Early Detection: Cancer detected at an early stage (before metastasis) is much easier to treat. Type and Stage of Cancer: Different cancers respond differently to treatments. Genetic Profile of the Tumor: Identifying specific mutations helps in targeted therapy. Patient's Overall Health: Age, immune status, and underlying conditions affect treatment tolerance. Access to Treatment: Availability of advanced therapies (immunotherapy, targeted therapy). Multidisciplinary Approach: Combining surgery, chemotherapy, radiation, and immunotherapy.

5. How marine biotechnology is important in Medicinal and Cosmetic Products?

Answer: Marine biotechnology is important in medicinal and cosmetic products because marine organisms produce unique bioactive compounds.

Medicinal Products:

Anticancer Drugs: Compounds like cytarabine (from a marine sponge) are used in chemotherapy. Antibiotics: Marine bacteria produce novel antibiotics. Anti-inflammatory Agents: Compounds from corals and algae.

Cosmetic Products:

Moisturizers and Anti-aging: Algae extracts rich in antioxidants and polysaccharides. UV Protectants: Compounds from cyanobacteria. Thickeners: Agar and carrageenan from seaweed.

6. (a) Which microbes are involved in baking and dairy products?

Answer:

Baking: Yeast (Saccharomyces cerevisiae) is used for leavening bread. It ferments sugars to produce CO₂ and ethanol. Dairy Products: Bacteria like Lactobacillus bulgaricus, Streptococcus thermophilus, and Lactococcus lactis are used to make yogurt, cheese, and buttermilk.

(b) What is the source of the sugars that are fermented in brewing?

Answer: The sugars fermented in brewing come from malted barley. Barley grains are germinated (malting), which produces enzymes (amylases) that convert stored starch into fermentable sugars (mainly maltose).

(c) How do bubbles of carbon dioxide make the bread rise?

Answer: During bread making, yeast ferments sugars in the dough, producing carbon dioxide gas. The CO₂ bubbles are trapped in the gluten network of the dough. As the dough bakes, the bubbles expand, causing the bread to rise and become light and porous.

7. How Gene knockdown differs from Gene knockout?

Answer:

8. The diagram shows an important step of genetic engineering. (Diagram showing a plasmid and a DNA fragment being combined)

(a) Name the structures P, Q and R.

Answer:

P: Restriction enzyme (molecular scissors) cutting the DNA. Q: Foreign DNA fragment (gene of interest) with sticky ends. R: Plasmid vector (cut open with complementary sticky ends).

(b) What is the next step of this process?

Answer: The next step is ligation. DNA ligase is used to join the foreign DNA fragment (Q) into the plasmid vector (R), creating a recombinant DNA molecule.

9. Name three major genetic editing techniques.

Answer: Three major genetic editing techniques are:

1. CRISPR-Cas9: Uses a guide RNA and Cas9 enzyme to cut specific DNA sequences, allowing for insertion, deletion, or modification of genes.

2. TALENs (Transcription Activator-Like Effector Nucleases): Uses engineered proteins to target and cut specific DNA sequences.

3. ZFNs (Zinc Finger Nucleases): Uses zinc finger proteins fused to a nuclease to target and cut DNA.

1. What is the importance of biotechnology?

Answer: Biotechnology is of immense importance in various fields, improving human life and the environment.

1. Medicine and Healthcare:

Pharmaceuticals: Production of human insulin, growth hormone, interferon, and vaccines. Gene Therapy: Treating genetic disorders by replacing faulty genes. Diagnostics: PCR, ELISA, and monoclonal antibodies for disease detection.

Stem Cell Therapy: Regenerative medicine.

2. Agriculture:

GM Crops: Pest-resistant, herbicide-tolerant, drought-resistant, and nutritionally enhanced crops. Biofertilizers and Biopesticides: Sustainable alternatives to chemicals. Livestock: Improved breeding and disease resistance.

3. Environment:

Bioremediation: Using microbes to clean up oil spills, heavy metals, and pollutants. Waste Treatment: Biodegradation of industrial and domestic waste. Biofuels: Production of ethanol and biodiesel.

4. Industry:

Enzymes: Production of enzymes for detergents, food processing, and textiles. Biopolymers: Biodegradable plastics.

In summary, biotechnology has the potential to revolutionize medicine, agriculture, environment, and industry.

2. Describe fermentation in yeast and bacteria.

Answer: Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen. It is used in various industrial processes.

1. Fermentation in Yeast (Alcoholic Fermentation):

Organism: Saccharomyces cerevisiae.

Process: Yeast converts glucose into ethanol and carbon dioxide. Equation: C₆H₁₂O₆ [source symbol unavailable] 2C₂H₅OH + 2CO₂ + Energy (ATP) Applications: Baking (CO₂ makes dough rise), Brewing (ethanol production).

2. Fermentation in Bacteria (Lactic Acid Fermentation):

Organisms: Lactobacillus species. Process: Bacteria convert lactose (milk sugar) into lactic acid. Equation: C₆H₁₂O₆ [source symbol unavailable] 2C₃H₆O₃ (Lactic Acid) + Energy (ATP) Applications: Yogurt, cheese, sour cream, pickles.

In summary, fermentation in yeast produces ethanol and CO₂, while fermentation in bacteria produces lactic acid.

3. Give details of key areas for modern research on cancer biotechnology?

Answer: Modern cancer biotechnology research focuses on several key areas:

1. Immunotherapy:

Checkpoint Inhibitors: Drugs that block proteins (PD-1, CTLA-4) that stop T cells from attacking cancer. CAR-T Cell Therapy: Engineering patient's T cells to express chimeric antigen receptors (CARs) that target cancer cells. Monoclonal Antibodies: Antibodies designed to bind to specific cancer cell markers.

2. Targeted Therapy:

Small Molecule Inhibitors: Drugs that block specific enzymes or receptors involved in cancer growth (e.g., tyrosine kinase inhibitors). Gene Therapy: Replacing or silencing faulty genes.

3. Cancer Biomarkers:

Identifying molecular markers for early detection, prognosis, and treatment response.

4. CRISPR-Cas9 Gene Editing:

Editing genes to correct mutations or to engineer immune cells.

5. Precision Medicine:

Tailoring treatment based on the genetic profile of the tumor.

In summary, cancer biotechnology research is focused on developing more effective, targeted, and personalized treatments.

4. What are the objectives of genetic engineering? How is a gene transplanted?

Answer: Objectives of Genetic Engineering:

1. Improve Crop Yield and Quality: Develop pest-resistant, drought-tolerant, and nutritionally enhanced crops.

2. Produce Pharmaceuticals: Bacteria engineered to produce human insulin, growth hormone, and vaccines.

3. Gene Therapy: Correct genetic disorders by replacing faulty genes.

4. Industrial Applications: Produce enzymes, biofuels, and biodegradable plastics.

5. Understand Gene Function: Study gene regulation and function.

How a Gene is Transplanted (Steps):

1. Isolation: The gene of interest is isolated using restriction enzymes.

2. Vector Preparation: A vector (e.g., plasmid) is cut with the same restriction enzyme, creating complementary sticky ends.

3. Ligation: The gene is inserted into the vector using DNA ligase to form recombinant DNA.

4. Transformation: The recombinant DNA is introduced into a host cell (e.g., bacteria, plant cell).

5. Selection: Transformed cells are selected using marker genes (e.g., antibiotic resistance).

6. Expression: The host cell produces the protein encoded by the gene.

In summary, genetic engineering aims to modify organisms for useful purposes, and gene transplantation is a multi-step process.

5. How gene editing technique is important for agriculture improvement?

Answer: Gene editing techniques, particularly CRISPR-Cas9, have revolutionized agricultural improvement.

1. Crop Improvement:

Pest Resistance: Editing genes to make crops resistant to pests (e.g., Bt crops). Disease Resistance: Editing genes to resist viral, bacterial, and fungal diseases. Drought Tolerance: Modifying genes to improve water use efficiency. Herbicide Tolerance: Making crops resistant to specific herbicides.

2. Nutritional Enhancement:

Biofortification: Increasing vitamin and mineral content (e.g., Golden Rice). Improved Oil Content: Modifying oil composition for health benefits.

3. Livestock Improvement:

Disease Resistance: Editing genes in animals to resist diseases. Growth Rate: Enhancing growth and muscle mass.

4. Sustainability:

Reduced Chemical Use: Less need for pesticides and fertilizers.

Climate Resilience: Developing crops that can withstand climate change.

In summary, gene editing is a powerful tool for sustainable agricultural improvement.