Question

Cite the advantage of propagation by tissue culture technique.

Answer 1

Hint: Tissue culture being a new innovative way of propagation in which fragments of tissues are used that are obtained from animals or plants and then transferred to artificial nutrient rich growth medium.

Complete answer:
American pathologist Montrose Thomas Burrows coined the word tissue culture. It is also known as micropropagation and involves the growth cells from the tissues of multicellular organisms. It is used in both plants and animal cells but plant tissue culture is much more explored and a successful branch of tissue culture. It is a very important tool used to study cells of multicellular organisms as it provides an in vitro model of the tissues that can be maintained in the artificial laboratory environment and studied as well as manipulated.
Tissue culture of animal cells is known as cell culture. As diverse varieties of cells are found in multicellular organisms, each one of them have a different criteria with which they are maintained in the artificial environment. These cells have specific requirements of carbohydrates, fats, proteins, growth hormones, amino acids, gases and the physico-chemical environment (pH, temperature, osmotic pressure). These cells also require a surface to adhere or a suspension culture.
Tissue culture is a term which is mostly used for the plant tissue culture which is the process of growing little plantlets from different tissues obtained from plants. These tissues are maintained in a strictly controlled artificial environment and after sometime they can be planted in the natural environment.

Advantages of animal tissue culture –
-Physico-chemical and physiological conditions can be precisely controlled in the artificial in-vitro environment.
-Selective media are used to maintain the homogeneity of the cells so only one type of cells can grow on a particular media.
-The cells that are grown can be cryopreserved in liquid nitrogen and their growth can be resumed when required.
-The in vitro cultured cells can be used for cytotoxic studies to understand the effect of drugs on the living cells.
-Monoclonal antibodies can be produced with the hybridoma technology.

Advantages of plant tissue culture –
-As the growth of plantlets is in vitro, it is independent of season and can be grown throughout the year.
-A complete plant can be grown with a small fragment of tissue in a very short amount of time.
-Plants grown in-vitro are free from diseases and infections from virus and fungi.
-Small spaces can produce large numbers of plantlets.
-Some breeds of plants which are hard to be propagated naturally can be propagated with this technique.
-A single seed gives rise to a single plant but with tissue culture many plants can be produced from a small tissue.

Additional information:
Disadvantages –
-This process is expensive and requires a well-developed and maintained laboratory
-As the cells of plants or animals are cultured in-vitro there are chances that when they go into the natural environment they will be more susceptible to diseases.
-Sterile aseptic conditions shall be maintained throughout the procedure and if a minor contamination is developed in the culture the whole culture becomes useless.
-High experience and expertise are required.

Note: Different media are used for different cell culture like in animal tissue cultures natural media like plasma, lymph, serum and amniotic fluids are used whereas in plant tissue culture agar media with necessary nutrients is used.