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?

A Planaria worm is cut horizontally in the middle into two halves P and Q such that the part P contains the whole head of the worm. Another Planaria worm is cut vertically into two• halves R and S in such a way that both the cut pieces R and S contain half head each. Which of the cut pieces of the two Planaria worms could regenerate to form the complete respective worms ?

A. only P

B. only R and S

C. P, Rand S

D. P, Q, R and S

There are four tiny organisms A, B, C and D. The organism A is a parasitic protozoan which causes a disease known as kala-azar. The organism B is a microscopic single-celled animal which causes malaria disease in human beings. The organism C is a unicellular animal which can change its body shape according to need, it has no fixed shape. The organism D is also a unicellular animal which is slippet-shaped having a large number of tiny hair all around its body.

(a) Name the organisms A, B, C and D

(b) Name one characteristic body feature of organism A.

(c) Name the insect which carries organism Band transmits it from one person to another.

(d) What name is given to the asexual method of reproduction of

(i) organism A, and (ii) organism B?

(e) Where do organisms C and D live?

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.

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] ?