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 than that given in (b) above] ?

Two very small organisms X and Y both reproduce by the method of budding. Organism X is industrially very important because it is used in making alcohol from sugar. It is also used in making bread. Organism Y lives in freshwater. If organism Y gets cut into a number of parts accidently, each cut part can grow to form complete organism.

(a) What are organisms X and Y ?

(b) What is the name of the process in which X converts sugar into alcohol ?

(c) To which class of organisms does X belong?

(d) Name an important body feature of organism Y.

(e) Which organism is multicellular and which one is unicellular?

When a moist slice of bread was kept aside for a few days then some organism grew on it to form a white cottony mass which later turned black. When this slice of bread was observed through a magnifying glass, then fine thread-like projections and thin stems having bulb-like structures at the top were seen.

(a) What is the common name and scientific name of the organism which grew on the moist slice of bread ?

(b) How did this organism grow on the moist slice of bread automatically?

(c) What are the fine, thread-like projections on the surface of slice of bread known as ?

(d) What name is given to the knob-like structures and what do they contain ?

(e) What is the name of this method of reproduction ?

(f) Name one unicellular organism which reproduces by this method.

(g) Name two non-flowering plants which reproduce by this method.

The stem of a fruit tree X fixed in soil is cut in a slanting way. The upper part of stem of another fruit tree Y of different variety of same species is also cut in a slanting way. The cut stem of tree Y, without roots but having some leaves, is placed over the rooted cut stem of tree X in such a way that their cut surfaces fit together properly. While joining the two cut stems, care is taken to make sure that the layer Z of one cut stem is in contact with layer Z of the other cut stem. The joint of cut stem is bound tightly with a piece of cloth and covered properly with polythene. Soon the cut heals and the two stems grow together and become one fruit tree producing leaves, flowers and fruits.

(a) What is the name of this method of producing plants or trees ?

(b) What name is given to the cut stem of tree X having roots?

(c) What name is given to the cut stem of tree Y which has no roots but has some leaves ?

(d) Name the layer Z.

(e) Why should the layer Z of one cut stem be in contact with the layer Z of the other cut stem ?

(f) Name y four fruit trees which are usually bred by this technique.

(g) State any one advantage of producing fruit trees by this technique.

A small part of the shoot of a plant is removed with a sharp knife. When the lower end of this small part of the shoot is buried in moist soil, it gradually develops roots and shoots and grows to become a new plant.

(a) What is the name of this method of propagating plants?

(b) What care should be taken while removing a small part of the shoot from the parent plant with a knife?

(c) Name any two plants which provide us with food directly or indirectly and are grown by this method.

(d) Give one advantage of this method of producing new plants.

(e) State whether it is a sexual method of reproduction or an asexual method. Why?

(f) What special name can be given to the genetically identical new plants produced by this technique?