Biotechnology
Chapter - 14
Biology
Q/A
1. How is culture medium prepared?
Ans: For the growth of the plant culture, culture media are made by mixing proper amount of essential minerals nutrients, vitamins, phytohormones, sucrose and condensing substance agar to bring the medium to a semi-solid state.
2. What is tissue culture?
Ans: Generally, one or a group of cells of the same type is called tissue. The process of growing a tissue on a nourishing and sterilized medium is tissue culture. Tissue culture is comparatively a new branch of botany.
3. What is explant?
Ans: The part of a plant, begin separate with the view of using it in tissue culture, is called explant.
4. What is genetic engineering?
Ans: With the view of changing the body of organism in quality by special technique of biotechnology, changing of gene particle in the centre of a cell is called genetic engineering.
5. What is transgenic?
Ans: With genetic engineering technology the transfer of the desired part of DNA from bacteria to human being, from plant to animal and animal to plant have become possible. The organism with the new characters is called GMO ( Genetically Modified Organism) or GE ( Genetically Engineered) or transgenic.
6. Mention the roles of tissue culture in plant reproduction and developing improved varieties of plants.
Ans: By utilizing the tissue culture, now a days in the reproduction of plants and in field of developing new variety, much achievement has been obtained and new horizons have evolved with the vast hopes. From the plant part in a short period of time, innumerable plantlets can be produced with the same characters. Easily disease free and especially free from viruses, plantlets can be produced. It can be free from the limitation of producing plantlets in short period of time in a very conspicuous place, sufficient number of plantlets can be produced and the problem of storing of seeds can be avoided. The attainment of plantlets of those which do not reproduced by seeds and they can be speedily transferred in a short period of time in fresh condition. Tissue culture technology is well accredited for the production and conservation of the species about to be extinct. The plants, which do not produce endosperm can be developed directly by culturing their embryo. The rapid multiplication of the plants, which do not reproduce through. Sexual reproduction of which rate of natural reproduction is low, can be done by culturing their embryo. Tissue culture technology is being used for the development of the plants of new characters. Disease resistant and high yielding plantlets of banana, wood apple, jackfruit have been produced because of tissue culture Garland chrysanthemum, gladiolus, lily, garden carnation etc. flower producing plantlets also have been produced. Cadamba, Jarul, epil, bakul, teak, nim etc. timer producing plantlets have been produced. Plantlets of different types of pulse, groundnut, jute have also been produced. It has become possible to produce disease free plantlets and seed microtuber of potato applying tissue culture.
7. Discuss the roles of genetic engineering in improving crops.
Ans: Genetic engineering or recombinant DNA technology is the most modern biotechnology. The main objective of the technology is to develop organisms with new and advance characters and by which human beings can be benefited surpassingly. By this time, notable successes have already been achieved through this technology. Harmful insects resistant varieties of crops have been developed, such as Bt corn, Bt cotton, Bt rice (developed in China) etc. These fruits are resistant to the harmful insects under Lepidoptera and Coleoptera orders. For the insertion of bacterial genes named Bacillus thuringiensis into the crops, These genetically modified crops are designated as Bt corn. Using this technology, virus resistant varieties of crop have been developed, for instance by transferring gene, tomato mosaic virus (TOMV), tobacco mosaic virus (TMV) and tobacco mild green mosaic virus ( TMGMV) resistant varieties of crop have been developed. The variety of papaya resistant to ring spot virus (PRSV) has also been developed. The research is being carried out for the development of late blight resistant variety of potato by transferring late blight fungus resistant gene. Varieties of corn and cotton tolerant to herbicides have been produced by genetic modification. Scientists have become able to develop herbicides tolerant variety of tomato by transferring herbicides tolerant variety of tomato by transferring herbicides tolerant genes into the tomato from a kind of bacteria. This way herbicides tolerant varieties of soyabean, corn, cotton, canola etc. have been produced. Through genetic engineering more than one fruit can be inserted in the same plant. Now a days, with no trouble this type of transgenic plants is commercially available. For instance, side by side both herbicides tolerant and insect resistant characters have been inserted in corn and cotton.
Through genetic change, nutrition value of some crops has been improved. For example, vitamin i.e. beta-carotene gene has been transferred into rice. Taking efforts to add iron in rice is being continued. The attempts are also being made to develop salinity and drought resistant varieties of different crops through genetic modification.
Multiple Choice Questions
1. Which one is a special enzyme to cut DNA?
a. Ligase
b. restriction
c. lactase
d. lipase
2. Biotechnology is applied to -
i. fermentation
ii. tissue culture
iii. develop transgenic organism
Which one of the following is correct?
a. i & ii
b. i & iii
c. ii & iii
d. i, ii & iii
Read following stem and answer the questions 3 and 4.
Imtiaz found a very good variety of woodapple visiting his friend's house. To produce the plantlets with the same characteristics, he brought some lateral buds of the plant, and produced them in the university lab of the Botany department.
1. What is the process that Imtiaz followed in the lab?
a. transfer of gene
b. application of hormone
c. use of enzyme
d. tissue culture
2. Which one shows the consecutive steps of Imtiaz's activities?
a. preparation of culture media ---> inoculation of explant ----> development of plantlets ------->
development of roots --------> transfer to natural environment
b. preparation of culture media ----------> development of plantlets ---------> development of roots ----->
inoculation of explant ----------> transfer to natural environment
c. selection of mother plant -------> preparation of culture media -------------> inoculation of explant ----------> development of plantlets -----------> transfer to natural environment
d. selection of mother plant ------------> preparation of culture media ----------> development of callus -------------------> development of callus---------------> transfer to natural environment
Creative Questions
1. In the garden belonging to a genetic engineer Dr. Hayder, the lemon plants are dying rapidly from disease through the lemon harvest is high. He finds that there are some lemon trees of the same species, which live for long time although they do not produce high yield. From these two variety. He produced the plantlets not using a traditional process but by a special process in his lab.