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प्रश्न
What determines whether the two organisms of a species will be exactly similar or not?
उत्तर
The similarity or difference between the organisms of a species depends upon whether these individuals are formed by sexual reproduction or asexual reproduction.
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संबंधित प्रश्न
Name the part of Bryophyllum where the buds are produced for vegetative propagation.
Draw a labelled diagram to show that particular stage of binary fission in amoeba in which its nucleus elongates and divide into two and a constriction appears in its cell membrane.
How are the modes for reproduction different in unicellular and multicellular organisms?
A tadpole develops into an adult frog by the process of ______.
External fertilisation takes place in frogs.
What is vegetative propagation?
State whether the following statement is true or false :
Spores produced by the bread mould plant are actually its seeds.
Name one organism which reproduces by spore formation
Name the artificial propagation mehod used for the propagation of apple trees.
What is the difference between the two asexual methods of reproduction : fission and fragmentation?
What is meant by 'grafting' as a means of propagation in plants?
What care should be taken while making a cutting from a plant?
One of the following organisms does not reproduce by budding. This is :
(a) Sponge
(b) Yeast
(c) Hydra
(d) Planaria
One of the following reproduces by forming spores. This in :
(a) Fern
(b) Planaria
(c) Spirogyra
(d) Potato
In Spirogyra, asexual reproduction takes place by :
(a) division of a cell into two cells
(b) breaking up of filaments into smaller bits
(c) division of a cell into many cells
(d) formation of a large number of buds
Spore formation is the most common asexual method of reproduction in :
(a) protozoa
(b) tubers
(c) fungi
(d) algae
Multiple fission occurs in one of the following. This is :
(a) bread mould
(b) kala-azar parasite
(c) flatworm
(d) malaria parasite
An organism which can reproduce by two asexual reproduction methods one similar to the reproduction in yeast and the other similar to the reproduction in Planaria is :
(a) Spirogyra
(b) Bryophyllum
(c) Hydra
(d) Sea anemone
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]?
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.
When the branches of a plant growing in the field are pulled towards the ground and a part of them is covered with moist soil (leaving the tips of the branches exposed above the ground), then after some time new roots develop from the parts of branches buried in the soil. On cutting these branches from the parent plant, new plants are produced from the cut parts of branches which had developed roots.
(a) What is this method of propagation of plants known as?
(b) What type of branches should a plant have to be able to be propagated by this method?
(c) Name any two plants which are grown for their flowers and propagated by this method.
(d) Name any two plants which are grown for their fruits and propagated by this method
(e) Name one plant which gets propagated by this method naturally by forming runners (soft horizontal stems running above the ground).
Why is it disadvantageous to grow plants vegetatively?
Write a short note on Micro propagation.
Fill in the blank:
Amoeba reproduces by _________.
Mention the common method of reproduction in Ferns.
List two advantages of vegetative reproduction practiced in case of an orange plant.
A student after viewing a prepared slide illustrates the budding in yeast in the following order which is not correct:
(A) b, c, d, e, a
(B) b, e, d, c, a
(C) b, d, e, c, a
(D) b, d, c, e, a
Give the name of the plant that reproduces vegetatively by: Stem-cutting
Explain the importance of the reproduction process.
- Which type of reproduction is indicated in the following diagram?
- Redraw the given type of reproduction in the correct sequence and explain it.
Draw a neat and labelled diagram.
Spore formation
Spirogyra reproduce by ______
Spirogyra reproduces by ______.
In the diagram given in Figure 12.2 label the parts marked (a), (b) and (c).
When you keep food items like bread and fruits outside for a long time, especially during the rainy season, you will observe a cottony growth on them.
What is this growth called?
The "Eyes" of the potato tuber are ______.
Plants like (vlmus), Dandelion (Taraxacum) and members of Rose family vegetative reproduce by ______.
