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प्रश्न
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 tow non-flowering plants which reproduce by this method.
उत्तर
(a) The common name of the organism is bread mould, and its scientific name is Rhizopus.
(b) Spores of fungus are present in the air in their inactive form. When these spores get the favourable condition like a moist bread, they germinate and grow into new organisms.
(c) The fine, thread-like projections on the surface of the bread are known as hyphae.
(d) The knob-like structures are sporangium, which contain the spores.
(e) This method of reproduction is known as spore formation.
(f) Mucor fungus reproduces by the method of spore formation.
(g) Ferns and mosses are two non-flowering plants which reproduce by this method.
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संबंधित प्रश्न
Identify the figures showing the process of budding in yeast.
(A) I, II and III
(B) II, III and IV
(C) I, II and IV
(D) III, IV and I
What is vegetative propagation?
what is the name of the process by which Amoeba reproduces?
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 any four fruit trees which are usually bred by this technique.
(g) State any one advantage of producing fruit trees by this technique.
Differentiate between the following:
Cutting and grafting
Mention the common method of reproduction in Spirogyra.
What is regeneration in organism?
The plants produced as a result of vegetative reproduction are
Match the columns:
| Column A (Asexual) | Column B (Examples) | ||
| (a) | Spore formation | (1) | Spirogyra |
| (b) | Conidia formation | (2) | Yeast |
| (c) | Fragmentation | (3) | Chlamydomonas |
| (d) | Budding | (4) | Penicillium |
