ROUTERA


Chapter 11 BiotechnologyPrinciples and processes

Class 12th Biology Chapter Case Study


Case Study 1: Genetic Engineering and Recombinant DNA Technology

Genetic engineering involves the manipulation of an organism's genome using biotechnology tools. One of the major techniques used in genetic engineering is recombinant DNA (rDNA) technology. This process involves the isolation of a gene of interest from one organism and inserting it into the DNA of another organism, creating a recombinant organism. For example, in insulin production, the gene for insulin is inserted into Escherichia coli (E. coli) bacteria. These bacteria, now genetically modified, can then produce human insulin in large quantities.

Questions:

  1. In recombinant DNA technology, the foreign gene is inserted into the host organism’s genome using a:

    • A) Restriction enzyme
    • B) Ligase enzyme
    • C) Reverse transcriptase
    • D) Polymerase chain reaction

    Answer: A) Restriction enzyme

  2. Which of the following is a major benefit of using E. coli in genetic engineering for insulin production?

    • A) It produces human insulin in large quantities
    • B) It produces toxins that help in medical research
    • C) It can survive in extreme environments
    • D) It does not require a host organism for reproduction

    Answer: A) It produces human insulin in large quantities

  3. The process of creating a recombinant DNA molecule involves:

    • A) Inserting the foreign gene into a plasmid vector
    • B) Using only natural DNA from the donor organism
    • C) Increasing the bacterial growth without gene insertion
    • D) Only using synthetic genes from the target organism

    Answer: A) Inserting the foreign gene into a plasmid vector

  4. Recombinant DNA technology is used in producing:

    • A) Antibiotics
    • B) Synthetic vitamins
    • C) Genetically modified crops
    • D) All of the above

    Answer: D) All of the above


Case Study 2: Cloning and Applications of Biotechnology

Cloning refers to the process of creating an organism or a cell with identical genetic material. One of the most famous examples of cloning is Dolly the sheep, which was the first mammal cloned from an adult somatic cell in 1996. The process of cloning involves somatic cell nuclear transfer (SCNT), where the nucleus from a somatic cell is transferred into an egg cell from which the nucleus has been removed. Cloning technology has potential applications in medicine, agriculture, and conservation.

Questions:

  1. In somatic cell nuclear transfer (SCNT), the nucleus is transferred from:

    • A) An egg cell to a somatic cell
    • B) A somatic cell to an egg cell
    • C) A stem cell to a somatic cell
    • D) An adult cell to a virus

    Answer: B) A somatic cell to an egg cell

  2. Dolly the sheep, the first mammal cloned from an adult somatic cell, was created using:

    • A) Embryo splitting
    • B) Somatic cell nuclear transfer (SCNT)
    • C) Artificial insemination
    • D) Cross-breeding

    Answer: B) Somatic cell nuclear transfer (SCNT)

  3. Cloning has potential applications in:

    • A) Agricultural improvements
    • B) Organ regeneration for transplants
    • C) Endangered species conservation
    • D) All of the above

    Answer: D) All of the above

  4. Which of the following is NOT a challenge associated with cloning?

    • A) Low success rate in animals
    • B) Ethical concerns regarding cloning of humans
    • C) Potential for genetic diversity loss
    • D) Increased risk of diseases in cloned organisms

    Answer: D) Increased risk of diseases in cloned organisms


Case Study 3: Bioreactors in Biotechnology

A bioreactor is an environment that provides optimal conditions for the growth of microorganisms or cells to carry out biotechnological processes. It is often used in the production of valuable products such as antibiotics, vaccines, and enzymes. In industrial biotechnology, fermentation in bioreactors is used for mass production of substances like penicillin and ethanol. Bioreactors maintain temperature, pH, and oxygen levels, which are crucial for efficient microbial growth and product yield.

Questions:

  1. The role of a bioreactor in industrial biotechnology is to:

    • A) Maintain optimal environmental conditions for microbial growth
    • B) Replace traditional agricultural processes
    • C) Synthesize recombinant DNA molecules
    • D) Produce only genetically modified organisms

    Answer: A) Maintain optimal environmental conditions for microbial growth

  2. In fermentation, microorganisms like Saccharomyces cerevisiae are used to:

    • A) Produce antibiotics
    • B) Break down sugars into ethanol and carbon dioxide
    • C) Synthesize insulin
    • D) Degrade organic waste

    Answer: B) Break down sugars into ethanol and carbon dioxide

  3. Penicillin production in bioreactors is an example of:

    • A) Drug synthesis using chemical processes
    • B) Microbial fermentation
    • C) Plant-based drug production
    • D) Transgenic plant biotechnology

    Answer: B) Microbial fermentation

  4. Bioreactors are widely used in the pharmaceutical industry for the production of:

    • A) Biocontrol agents
    • B) Vaccines and antibiotics
    • C) Gene-editing tools
    • D) All of the above

    Answer: B) Vaccines and antibiotics


Case Study 4: PCR - Polymerase Chain Reaction

Polymerase Chain Reaction (PCR) is a method used to amplify small segments of DNA for further analysis. In this process, a DNA sample is heated to separate its strands, and then Taq polymerase is used to replicate the DNA strands in cycles. PCR is used in a variety of applications, including genetic research, forensic science, and medical diagnostics. It allows scientists to create millions of copies of a DNA segment from just a few initial molecules.

Questions:

  1. The key enzyme used in PCR to amplify DNA is:

    • A) Ligase
    • B) Reverse transcriptase
    • C) Taq polymerase
    • D) DNA polymerase I

    Answer: C) Taq polymerase

  2. The purpose of heating the DNA sample during PCR is to:

    • A) Facilitate the binding of primers
    • B) Separate the double-stranded DNA into single strands
    • C) Add nucleotides to the growing DNA strand
    • D) Inhibit the activity of DNA polymerase

    Answer: B) Separate the double-stranded DNA into single strands

  3. PCR is used in:

    • A) Cloning
    • B) Forensic DNA analysis
    • C) Amplifying specific gene sequences
    • D) All of the above

    Answer: D) All of the above

  4. PCR is an important technique because it allows scientists to:

    • A) Sequence entire genomes
    • B) Amplify a specific region of DNA
    • C) Synthesize proteins
    • D) Perform gene editing

    Answer: B) Amplify a specific region of DNA


Case Study 5: Applications of Biotechnology in Agriculture

Biotechnology has led to the development of genetically modified (GM) crops, which have been engineered for improved qualities like increased resistance to pests, herbicides, and diseases, as well as enhanced nutritional content. One example is Bt cotton, which contains a gene from the bacterium Bacillus thuringiensis that makes it resistant to certain pests. Another example is the development of golden rice, which has been genetically modified to produce beta-carotene, a precursor of vitamin A.

Questions:

  1. Bt cotton is genetically modified to resist:

    • A) Fungal diseases
    • B) Bacterial infections
    • C) Insect pests
    • D) Herbicides

    Answer: C) Insect pests

  2. Golden rice is genetically modified to produce:

    • A) Higher yields
    • B) Higher protein content
    • C) Beta-carotene (vitamin A precursor)
    • D) More edible parts

    Answer: C) Beta-carotene (vitamin A precursor)

  3. The use of genetically modified crops in agriculture helps in:

    • A) Reducing the use of chemical pesticides
    • B) Increasing crop resistance to environmental stresses
    • C) Improving the nutritional quality of crops
    • D) All of the above

    Answer: D) All of the above

  4. The gene used in Bt cotton comes from:

    • A) A virus
    • B) A bacterium
    • C) A fungus
    • D) A plant

    Answer: B) A bacterium