A scientist removed some cells from the growing point of a plant and placed it in a suitable medium leading to the formation of a shapeless lump of mass X. X is then transferred to another medium which stimulates it to develop roots. When X with developed roots is placed in a yet another medium, then it develops shoots to form tiny plantlets. These plantlets can then be transplanted in pots or soil where they can grow to form mature plants.
(a) What is the shapeless lump of mass X known as?
(b) What name is given to this method of producing new plants?
(c) The growth medium used in this method contains plant nutrients in the form of a 'jelly'. Name this jelly.
(d) What is the general name of chemicals used to stimulate the growth of plant cells and development of roots and shoots?
(e) Name any two plants which are produced by this method.
(f) State any two advantages of this method of producing plants.
(g) What is the other name of this method [other then that given in (b) above]?

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Solution

(a) The shapeless lump of mass X is known as callus.
(b) This method of producing new plants is known as tissue culture.
(c) The jelly is called agar.
(d) The chemicals used to stimulate the growth of plant cells and fasten the development of roots and shoots are called plant hormones.
(e) Orchids and dahlia are two flowering plants that are propagated by this method.
(f) The main advantage of this technique is that it is extremely fast, and the plantlets are obtained in a few weeks. Secondly, this method produces disease-free plantlets.
(g) The other name of this technique is micropropagation.

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