Long answer type questions
1. Describe the various steps involved in tissue culture.
2. What are the advantages of vegetative reproduction?
3. What happens after successful pollination?
4. Explain with examples, the different ways in which seeds disperse.
Answers
1.The steps are: 1. Inoculation of Explant 2. Incubation of Culture 3. Sub-Culturing 4.The following four main steps of tissue culture techniques. The steps are: 1. Inoculation of Explant 2. Incubation of Culture 3. Sub-Culturing 4. Transplantation of the Regenerated Plant.
Step # 1. Inoculation of Explant:
Successful control of contamination largely depends upon the precautions taken to prevent the entry of microorganisms at the time of transferring the sterilised explants on the nutrient medium. Dust, hair, hands and clothes are the potential sources of contamination. The inoculating chamber should be dust free the operator should wear sterile headgear and clothes (aprons) before entering the culture area.The following four main steps of tissue culture techniques. The steps are: 1. Inoculation of Explant 2. Incubation of Culture 3. Sub-Culturing 4. Transplantation of the Regenerated Plant.
Step # 1. Inoculation of Explant:
Successful control of contamination largely depends upon the precautions taken to prevent the entry of microorganisms at the time of transferring the sterilised explants on the nutrient medium. Dust, hair, hands and clothes are the potential sources of contamination. The inoculating chamber should be dust free the operator should wear sterile headgear and clothes (aprons) before entering the culture area.The following four main steps of tissue culture techniques. The steps are: 1. Inoculation of Explant 2. Incubation of Culture 3. Sub-Culturing 4. Transplantation of the Regenerated Plant.
Step # 1. Inoculation of Explant:
Successful control of contamination largely depends upon the precautions taken to prevent the entry of microorganisms at the time of transferring the sterilised explants on the nutrient medium. Dust, hair, hands and clothes are the potential sources of contamination. The inoculating chamber should be dust free the operator should wear sterile headgear and clothes (aprons) before entering the culture area.Step # 2. Incubation of Culture:
After inoculation, the cultures are incubated in culture room or in a BOD incubator at 25±2°C temp. For certain plant or for some particular culture type below or above 25°C is needed.Step # 3. Sub-Culturing:
The growth and development of tissues cultured in vitro are generally monitored by observing the cultures at regular intervals in the culture room or incubators.
Based on the observations either with hand-lens or with the aid of simple microscope under aseptic conditions, the explants may be required to transfer to new media (freshly prepared) or with new ingredients or hormone composition depending on the state of growth of cell or tissue.Step # 4. Transplantation of the Regenerated Plant:
Plants regenerated from in vitro tissue culture are transplanted to soil in pots. Prior to transfer to pots the acclimatization of these regenerated plants are needed. The plants at this time develop adequate root systems and cuticular leaf surface structure so that it can withstand the field environmental condition.
2.There are several advantages of vegetative reproduction, mainly that the produced offspring are clones of their parent plants. If a plant has favorable traits, it can continue to pass down its advantageous genetic information to its offspring.
3.Only after pollination, when pollen has landed on the stigma of a suitable flower of the same species, can a chain of events happen that ends in the making of seeds. The fertilised ovule goes on to form a seed, which contains a food store and an embryo that will later grow into a new plant.
4.There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus.