Information and Communication Technology · Classes 11-12 · Chapter 1 · 1.3.9 and 1.3.10

Genetic Engineering and Nanotechnology.

A modified bacterium makes human insulin, and rice grows purple. Behind both is the trick of working on a gene. And when a thing shrinks to a billionth of a metre, its very nature can change. This note puts two technologies side by side: genetic engineering and nanotechnology.

1. From cell to genome

Every living body is made of countless cells. Inside each cell are chromosomes, and chromosomes are built from DNA (Deoxyribo Nucleic Acid) in a double helix. The tiny parts inside DNA that carry the traits of a living thing are called genes.

The human body has 20,000 to 30,000 genes. One set of genes is a genome, the design or arrangement of an organism's traits. A genome sequence is the order of the complete DNA arrangement of a cell, and the longer a genome is, the more information it holds.

Before you sort, zoom down the ladder: from the body to a cell, from the cell to a chromosome, then to DNA and the gene.

Put five terms in order from big to small, with the set coming last.

2. Changing a gene to make something new

A gene carries a trait, so changing a gene can change that trait. In a laboratory that part of the DNA is cut out, and a gene from another organism or a bacterium is brought in and attached.

Change one gene and attach another in its place, and what you get is recombinant DNA (rDNA). An organism carrying rDNA is a Genetically Modified Organism (GMO).

The whole technique is called genetic engineering: arranging a genome as needed, or joining the genomes of several organisms, to create new cells.

3. Benefit and harm

Genetic engineering has produced high-yield or hybrid rice, crops, animals and fish. These help against food shortage, and animals can be made larger with more protein in their meat and milk.

Modified E. Coli bacteria and yeast make human insulin. Gene technology is also used for hormones and for treating dwarfism, viral diseases, cancer and AIDS.

Work is going on at home too. The Bangladesh Rice Research Institute (BRRI), the Jute Research Institute and the Sugarcane Research Institute all work with genetic engineering. BRRI developed high-yield rice and a purple high-yield rice. A team led by Dr. Maqsudul Alam discovered the genome sequence of jute, which can restore the lost glory of the golden fibre.

There is a flip side: abnormal changes in biodiversity, unethical gene transfer, weaker antibiotics and allergies, and the risk of deadly new species or viruses. Sort eight chips into the benefit box and the harm box.

4. The nanometre and the nano particle

One nanometre is 10⁻⁹ metre. Making and using anything of 1 to 100 nanometres with science and technology is nanotechnology, and anything of that size is a nano particle. An example is C60, made of 60 carbon atoms.

Because it is so small, a nano particle has a much larger surface area for its size, which makes it chemically far more reactive. Quantum effects also show up, so its properties can change.

Nanotechnology works in two ways. Bottom Up: start from tiny molecular parts and slowly build something large. Top Down: take something large and reduce it to a small one.

5. Eight fields of nano

The book lists eight fields where nanotechnology is used. Tap each chip to see its use, in the book's order.

The book names the harms of nanotechnology too: making deadly weapons, misuse as a fuel substitute, black marketing, and altering the make-up of cells.

6. Know the terms

Six terms from this note, each a one-line definition. Say it yourself first, then turn the card.

7. Check yourself

Three questions in the exam's style. Start with the first.

In the second, keep the terms apart.

Think a little before the last one.

The whole note on seven cards.

Source: Information and Communication Technology, Classes 11-12 (NCTB), Chapter 1 “Information and Communication Technology: World and Bangladesh Perspective”, section 1.3.9 and 1.3.10.