Biology Biotechnology Applications part 13 (Questions) class 12 XII | Summary and Q&A

TL;DR

This video discusses the applications of biotechnology, including the use of bacterial toxins and genetic engineering to produce insect-resistant crops and human proteins.

Key Insights

• 😥 BT toxin crystals are inactive until ingested by insects, at which point they become activated and kill the insect by breaking down its digestive tract.
• 🎙️ Cry proteins, produced by BT bacteria, are toxic insecticidal proteins used to develop insect-resistant transgenic crops.
• 😑 Cloning and expressing a human gene into bacteria involves creating recombinant DNA and inserting it into the target bacteria to produce the desired protein.
• 🩸 Human blood does not have proteases and nucleases to protect its proteins from degradation.

Transcript

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Questions & Answers

Q: Why do the crystals of BT toxin produced by bacteria not kill the bacteria themselves?

The crystals of BT toxin are inactive and only become activated when ingested by an insect due to the alkaline environment of the insect's gut. The inactive form of the toxin is known as protoxin, which is converted into an active toxin once ingested by the insect.

Q: What are cry proteins and how are they used in biotechnology?

Cry proteins are toxic insecticidal proteins produced by organisms like BT bacteria. These proteins have been exploited in biotechnology to develop transgenic crops that are resistant to insects. When the cry protein gene is inserted into plants, they produce the protein, making them toxic to insects when eaten.

Q: Can you explain the process of cloning and expressing a human gene in bacteria?

Cloning and expressing a human gene, such as growth hormone, into bacteria like E.coli involves creating recombinant DNA by combining the bacterial plasmid DNA and the human gene of interest. This recombinant DNA is then inserted into the target bacteria, allowing them to produce the desired protein.

Q: Why doesn't human blood have proteases and nucleases?

Human blood does not contain proteases and nucleases to protect the proteins present in the blood from degradation. The presence of these enzymes could lead to the breakdown of blood proteins, which is undesirable.

Q: What are transgenic bacteria and can you provide an example?

Transgenic bacteria are genetically modified organisms that have a foreign gene intentionally introduced into them. An example of transgenic bacteria is E.coli, which can be modified to produce human insulin by inserting the gene responsible for insulin production into the bacteria.

Summary & Key Takeaways

• BT toxin crystals produced by bacteria are inactive until ingested by insects, at which point they activate and kill the insect by breaking down its digestive tract.

• Cry proteins, produced by organisms such as Bacillus thuringiensis (BT) bacteria, are toxic insecticidal proteins that have been exploited to develop insect-resistant transgenic crops.

• Cloning and expressing a human gene, such as growth hormone, into bacteria like E.coli involves creating recombinant DNA and inserting it into the target bacteria to produce the desired protein.

• Human blood does not contain proteases and nucleases, enzymes that break down proteins and nucleic acids, to protect the blood's proteins from degradation.

• Transgenic bacteria, such as E.coli, are genetically modified organisms that have a foreign gene intentionally introduced into them. An example is the insertion of a human insulin gene into E.coli to produce human insulin.