Biotechnology Principles and Recombinant DNA

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Questions and Answers

What is the function of the origin of replication in a chromosome?

It is responsible for initiating DNA replication. (correct)

It acts as a site for protein synthesis.

It helps in controlling gene expression.

It initiates DNA transcription.

What role do plasmids play in genetic engineering?

They are involved in RNA synthesis.

They serve as vectors to transfer DNA. (correct)

They regulate gene expression within the nucleus.

They act as energy sources for cells.

Which enzyme is responsible for joining cut DNA molecules?

Restriction enzyme.

Helicase.

DNA polymerase.

Ligase. (correct)

Who were the scientists credited with the first successful construction of recombinant DNA?

Stanley Cohen and Herbert Boyer. Signup and view all the answers

What is the purpose of using restriction enzymes in genetic engineering?

To cut DNA at specific sites. Signup and view all the answers

What does the term 'cloning' refer to in a genetic context?

The creation of multiple identical copies of DNA. Signup and view all the answers

What happens when recombinant DNA is transferred into Escherichia coli?

It can replicate using the host's DNA polymerase. Signup and view all the answers

What is meant by 'autonomously replicating circular extra-chromosomal DNA'?

It describes plasmids that can replicate independently. Signup and view all the answers

What are the two core techniques that enabled the development of modern biotechnology?

Genetic engineering and maintenance of sterile ambience Signup and view all the answers

What is a primary benefit of sexual reproduction compared to asexual reproduction?

It allows for opportunities of variations. Signup and view all the answers

What limitation of traditional hybridization does genetic engineering overcome?

Including only desirable genes without undesirable genes. Signup and view all the answers

What is likely to happen to a piece of DNA transferred into an alien organism without integration?

It will not be able to multiply in the progeny cells. Signup and view all the answers

What is a significant outcome of integrating an alien piece of DNA into a host's genome?

The piece of DNA may enhance the phenotype of the host. Signup and view all the answers

What role does creating recombinant DNA serve in genetic engineering?

It enables the selection of desirable genetic traits. Signup and view all the answers

Why is maintaining a sterile ambience important in biotechnological processes?

It allows growth of only the desired organisms. Signup and view all the answers

Which aspect of genetic engineering differentiates it from traditional breeding methods?

It specifically targets desired traits without unwanted genes. Signup and view all the answers

What is the role of one of the antibiotic resistance genes mentioned in the content?

It assists in the selection of transformants. Signup and view all the answers

What occurs during the insertion of recombinant DNA into the β-galactosidase coding sequence?

The enzyme is inactivated. Signup and view all the answers

What characteristic do recombinant colonies show when a chromogenic substrate is present?

They do not produce any color. Signup and view all the answers

What is a challenge associated with using antibiotic resistance for selecting recombinants?

It requires simultaneous plating on multiple antibiotics. Signup and view all the answers

What is the purpose of using a chromogenic substrate in selecting recombinants?

To differentiate recombinants based on color production. Signup and view all the answers

Which organism is mentioned as able to transfer T-DNA to plants?

Agrobacterium tumefaciens Signup and view all the answers

What effect does T-DNA have on normal plant cells?

It transforms them into tumor cells. Signup and view all the answers

What is a function of retroviruses in animal cells as mentioned in the content?

They can convert normal cells into cancerous cells. Signup and view all the answers

What is the first step in recombinant DNA technology?

Isolation of the genetic material (DNA) Signup and view all the answers

Which enzyme is specifically used to break down bacterial cell walls to release DNA?

Lysozyme Signup and view all the answers

What is used to confirm the progress of DNA digestion by restriction enzymes?

Agarose gel electrophoresis Signup and view all the answers

Which treatment is used to remove RNA during the isolation of DNA?

Ribonuclease treatment Signup and view all the answers

The process of ligation in recombinant DNA technology refers to which step?

Joining the desired DNA fragment to a vector Signup and view all the answers

What role do restriction endonucleases play in recombinant DNA technology?

They cut DNA at specific sequences Signup and view all the answers

After isolating DNA, which step is performed next in the recombinant DNA process?

Fragmentation of DNA Signup and view all the answers

What is the purpose of culturing host cells in recombinant DNA technology?

To amplify the recombinant DNA and produce the desired product Signup and view all the answers

What is the primary function of the stirrer in a stirred-tank bioreactor?

To facilitate even mixing and oxygen availability Signup and view all the answers

Which component is NOT included in a stirred-tank bioreactor system?

Cooling system Signup and view all the answers

What are downstream processing techniques primarily focused on?

Separation and purification of the product Signup and view all the answers

What is necessary for the formulation of products after downstream processing?

Thorough clinical trials Signup and view all the answers

Which of the following is a key process that enables modern biotechnology?

Recombinant DNA technology Signup and view all the answers

What is the purpose of strict quality control testing for biotechnological products?

To guarantee product efficacy and safety Signup and view all the answers

Which of the following systems is specifically identified as part of the bioreactor's design?

Foam control system Signup and view all the answers

What role do sterile air bubbles play in a sparged stirred-tank bioreactor?

They facilitate oxygen delivery Signup and view all the answers

Study Notes

Principles of Biotechnology

Two core techniques that enabled modern biotechnology:
- Genetic engineering: manipulating DNA and RNA to introduce changes into organisms and alter their phenotypes.
- Sterile environments in chemical engineering processes to allow growth of desired microbes or eukaryotic cells for products like antibiotics, vaccines, and enzymes.

Recombinant DNA Technology

Traditional hybridization methods can introduce undesirable genes alongside desirable ones.
Genetic engineering overcomes this issue by isolating and introducing specific genes.
For an alien DNA fragment to multiply in a host organism, it needs to be integrated into a chromosome with an origin of replication.
First recombinant DNA molecule:
- Stanley Cohen and Herbert Boyer linked an antibiotic resistance gene to a plasmid from Salmonella typhimurium in 1972.
- They used restriction enzymes to cut the DNA and DNA ligase to join the gene with the plasmid.
- This recombined plasmid was transferred into Escherichia coli, where it replicated and its antibiotic resistance gene was cloned.

Gene Cloning

Cloning requires vectors to transfer the alien DNA into a host organism.
Plasmids are commonly used vectors, similar to how mosquitos transfer parasites.
In gene cloning, a selectable marker, often an antibiotic resistance gene, is used to identify bacteria with the inserted gene.
Alternative selectable markers use insertional inactivation of enzymes, leading to color changes in colonies.

Biotechnology Applications

Genetic engineering has been used to transfer genes into plants and animals, based on natural processes like those seen in Agrobacterium tumifaciens and retroviruses.
Agrobacterium tumifaciens delivers a T-DNA fragment that transforms plant cells into tumors.
Retroviruses in animals can transform normal cells into cancerous cells.

Steps in Recombinant DNA Technology

Isolation of DNA:
- Cells are treated with enzymes like lysozyme, cellulase, or chitinase to release DNA.
- RNA is removed with ribonuclease and proteins with protease.
- DNA is purified by precipitation with chilled ethanol.
Restriction enzyme digestion:
- Purified DNA is incubated with restriction enzymes under optimal conditions to cut DNA at specific locations.
- Progress is monitored using agarose gel electrophoresis, which separates DNA fragments based on size.
Ligation:
- DNA fragments are joined with a vector using DNA ligase, which seals the gaps between DNA ends.
Transformation:
- Recombinant DNA is introduced into a host organism, often bacteria, using methods like heat shock or electroporation.
Selection of recombinants:
- Recombinant cells with the desired gene are identified and isolated using selectable markers.
Multiplication or Expression:
- Recombinant cells are cultured in large-scale bioreactors to produce the desired product.
Downstream processing:
- The product is purified, formulated, and tested for quality before marketing.

Summary

Biotechnology focuses on large-scale production and marketing of products and processes using living organisms, cells, or enzymes.
Recombinant DNA technology, also known as genetic engineering, is the key process in modern biotechnology.
It involves altering the chemistry of DNA to construct recombinant DNA molecules.
Genetic engineering techniques are used to overcome limitations of traditional breeding methods and introduce specific genes into organisms.

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Description

Explore the foundational principles of biotechnology, focusing on genetic engineering and its role in modern science. This quiz covers the introduction of recombinant DNA technology, highlighting key historical milestones and techniques used in manipulating genes.