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]?
Answers
Answer:
a) X: callus
b) Tissue culture
c) agar
d) Phytohormones (cytokinin, auxin)
e) Arabidopsis, Rice, Banana etc.
f) Advantages of tissue culture:
1. Culturing of the selected desirable traits.
2. A large population of clones of a desired trait are obtained by this method.
g) Micropropagation
Explanation:
Micropropagation is a process in which the meristematic cells from a plant are obtained and cultivated in the artificial conditions. The cells are grown in a media containing cytokinin and auxin and other nutrients which are essential for the growth of the plant. Agar provides the solid media for the growth and a light source with adequate wavelength is also provided. The ex-plant so produced will be a clone and will have all the desirable traits.
Answer:
a) The shapeless lump of mass X that can grow to form mature plants is known as a callus.
(b) The method of producing new plants from selected cells when placed in a suitable medium is known as a tissue culture method.
(c) The jelly present in the growth medium during the tissue culture method, providing nutrients to plant, is known as agar.
(d) The chemical used to stimulate the growth of plant cells and the development of roots and shoots is known as a plant hormone or phytohormones.
(e) Plants that are produced by tissue culture method are rice, carnation, orchids, banana, dahlia, Arabidopsis, etc.