Ch 12Biotechnology — Class 12 Biology, concept-first.

Biotechnology is essentially the product of interaction between the biological sciences and technology -- an applied branch of biology that has been broadly defined as the development and utilisation…

Modern biotechnology rests on two core techniques: genetic engineering and chemical engineering. Genetic engineering deals with altering the genetic material itself (DNA and RNA), while chemical engin…

Before gene cloning can actually be carried out, certain basic requirements must be in place. These fall into two broad categories: the instruments (devices) needed to isolate, characterise and amplif…

DNA, RNA and proteins are macromolecules synthesised inside living cells, and they differ from one another in molecular weight, solubility, the charges they carry, and how they absorb light.

The polymerase chain reaction (PCR) is another key device used for gene cloning and gene multiplication in vitro -- it amplifies a chosen gene of interest.

Three types of biological tools are needed to transform a host cell with recombinant DNA: enzymes, cloning vectors (vehicle DNA), and competent hosts (cloning organisms).

Enzymes that cut the phosphodiester bonds of a polynucleotide chain are called nucleases, and they come in two types: exonucleases, which remove nucleotides from the ends of a DNA strand, and endonucl…

Cloning vectors, or vehicle DNA, are DNA molecules that carry a foreign DNA segment and replicate it inside a host cell.

The third biological tool needed is a competent host -- also called a cloning organism -- into which the recombinant DNA is finally transferred.

Once the required instruments and biological tools are in place, gene cloning itself proceeds through a fixed sequence of steps, summarised in Fig 12.5: isolating the desired gene from the donor organ…

The first step is obtaining the desired gene from its source (donor) organism. The donor's cells are first sheared, for example with a blender, and treated with a suitable detergent to break them open…

The foreign (passenger) DNA is next inserted into a cloning vector, or vehicle DNA. The most commonly used cloning vectors are bacterial plasmids and bacteriophage viruses such as lambda phage and M13…

The recombinant DNA is now introduced -- transferred -- into a competent host cell of a suitable cloning organism, usually a bacterium, so that the inserted gene can be expressed.

The transformation process always produces a mixed population of cells: some are successfully transformed (recombinant), and others are not (non-recombinant).

Once transformed cells have been picked out by this screening process, they are introduced into fresh culture medium.

The final step in the six-step methodology of rDNA technology is expression of the cloned gene, and it follows directly from the previous step: once the transformed host cells have been selected and a…

Biotechnology is an umbrella term covering a broad spectrum of scientific applications, used across many sectors -- health and agriculture, industry, environment and genomics.

Healthcare biotechnology refers to medicinal or diagnostic products, or vaccines, developed using biotechnology, and it has had a tremendous impact on meeting patient needs.

Insulin is a peptide hormone produced by the beta-cells of the islets of Langerhans in the pancreas; it was discovered by Sir Edward Sharpey-Schafer in 1916, while he was studying the islets of Langer…

A vaccine is a biological preparation that provides active acquired immunity against a specific disease.

In agriculture, biotechnology is applied mainly through genetically modified (GM) crops, produced by gene manipulation to be pest-resistant, stress-tolerant, or otherwise more productive.

Gene therapy is the treatment of a disease or disorder by replacing, altering, or supplementing a gene that is absent or abnormal, where that absence or abnormality is responsible for the disease.

Gene therapy takes two broad forms. (a) Germ-line gene therapy introduces healthy genes into germ cells -- sperm, eggs, or early embryos -- so that the corrected genetic information is transmitted to…

Genes can be delivered into cells in three main ways. (i) Ex vivo delivery -- cells are first removed from the patient, the therapeutic gene is introduced into them outside the body using a viral or n…

Genetically Modified Organisms (GMOs) are living organisms whose genetic material has been artificially manipulated in a laboratory through genetic engineering, creating combinations of plant, animal,…

Human agriculture depends heavily on continual improvement, and as the world's population keeps growing, agricultural practices must be constantly reassessed for efficiency.

GM food-plants offer several kinds of advantage.

A transgenic animal is one in which there has been a deliberate modification of the genome -- as opposed to a spontaneous mutation -- using recombinant DNA technology.

Ethics, in general, deals with matters of socially acceptable moral duty, conduct and judgement -- it helps regulate a community's behaviour according to a shared set of standards, though the specific…

(a) Herbicide use and resistance. Effects on the environment are a particular concern with GMO crops and food production.

(a) Allergies. GMO crops could potentially have negative effects on human health, including allergic reactions that were never anticipated.

A patent is a special right granted to an inventor by the government, and it is treated as the inventor's personal property -- it can be sold, like any other property.

Biopatents are awarded to recognise genuinely innovative contributions made by an inventor towards human welfare, and to encourage and value the development of scientific culture, emphasising biology'…

Where a pirate, in the ordinary sense, steals from and harms others to enrich themselves, a biopirate does not kill -- they steal a patent, or misuse the patent system.

Sample papers and previous-year board questions for this subject.