Q1. Define the following
- Biotechnology: - Biotechnology is an important branch of modern science, which operates at molecular level to bring out changes in the hereditary characteristic of organisms.
- Bioremediation: - Bioremediation can simply be defined as the use of biological organisms such as plants or micro organisms to remove hazardous chemicals or pollutants from water, waste water and soil.
Q2. Give scientific reasons.
1. In earlier days insulin was not affordable for common public.
- In diabetic condition, insulin is supplied externally to bring down the glucose level in the blood.
- This insulin was obtained from the animals such as horse.
- It is very costly affair.
- Hence, insulin was not available in required quantity and also at affordable cost for common public.
2. Biotechnology can be used to develop plants, which resists herbicides.
- Chemicals known as herbicides are used to kill the herbs. But these herbicides also kill crop plants.
- By using biotechnology we can develop plants which resist herbicides.
- This would allow the use of herbicides without affecting the crop plants.
- Hence, to avoid a major crop loss, biotechnology is used to develop plants, which resists herbicides.
3. Protein injection is better than vaccination.
- Vaccination may produce adverse effects and is a risk because killed or weakened disease causing microbes are injected into the body.
- In protein injection, instead of weakened or killed bacteria and viruses, the proteins produced by them are injected into the body in pure form.
- These proteins stimulate immune system protecting the person from diseases.
- Hence, protein injection is better than vaccination as it avoids the risks.
4. Hereditary diseases are non – curable.
- Many diseases are hereditary.
- It means that they are transmitted to the next generation from the parents.
- There is no cure for these hereditary diseases as they are caused due to faulty genes in the body of an individual.
- Hence, hereditary diseases are non – curable.
5. Transgenic potatoes cannot be cooked.
- Potatoes which make proteins of disease causing bacteria are called transgenic potatoes.
- When man or animal eat these potatoes their body would be immunized against cholera or diseases caused by a bacterial called Escherichia Coil.
- Cooking of such transgenic potatoes would destroy the ‘protein’ of disease causing bacteria.
- Hence, transgenic potatoes cannot be cooked.
Q3. Write shot notes on
1. Biotechnology in Agriculture.
- Efforts are being made to bring out genetic changes in the characteristics of plants and animals.
- The changes would result in production of new varieties of plants and animals.
- The main focus of crop research is to develop plants using biotechnology such that these plants survive drought and frost, environmental stresses which includes excess temperature.
- Through biotechnology we may be able to transfer characteristics like resistance towards insects and pests from one plant to another.
- Biotechnology can be used to develop plants which resist herbicides. This would allow the use of herbicides without affecting the crop plants.
- Biotechnology can be used to develop crop plants which gives high yields.
- In order to enhance the resistance to a particular disease a method called vaccination is used.
- In this process a disease causing virus or bacteria is either killed or weakened and injected in the body.
- Body would produce proteins which would kill viruses or bacteria which may enter the body at a later stage.
- Polio vaccine is an example of weakened live polio virus, not capable of causing diseases.
- In case of typhoid and cholera, vaccine, killed bacteria are used.
3. Waste water treatment.
- Waster water often contains lot of organic matter.
- When such waste water is released into natural water sources such as river, organic matter gets oxidised consuming dissolved oxygen in river water.
- When dissolved oxygen in water decreased, flora and fauna of water is adversely affected.
- Hence waste water is treated before its release.
- In such treatments microbial technology is used to oxidise organic matter before its release.
Q4. Answer briefly.
1. Describe in detail, the experiment carried out by Frederick Griffith.
- In 1928, Frederick Griffith carried out an important experiment which proved the existence of ‘transforming principle’.
- The experiment was done on mice using two types of bacteria of same kind. One of them caused pneumonia whereas other was harmless when living organisms of both types were injected in different mice.
- Those injected with disease causing bacteria died, whereas those with harmless types survived.
- When disease causing bacteria were heat killed and then injected, the mouse survived.
- But when heat killed disease causing bacteria were injected with living harmless bacteria in the same mouse, the mouse died.
- This showed that ther is some principle form dead bacteria which got transformed to living harmless bacteria and changed their properties to make them lethal.
- Years later scientist with great effort succeeded in isolating and identifying that the transforming principle involved was DNA.