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प्रश्न
Name and differentiate between the two modes of pollination in flowering plants.
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उत्तर
Two types of pollination can be found in flowering plants:-
- Self-pollination
- Cross-pollination
Differences between the two are given below:-
| Self-Pollination | Cross-Pollination |
| The pollen needs to be transferred from the stamen to the stigma. If this transfer of pollen occurs in the same flower, it is referred to as self-pollination. | The pollen is transferred from one flower to another, it is known as cross-pollination. |
| It occurs in bisexual flowers. | It occurs in both bisexual and unisexual flowers. |
| It refers to the transfer of pollen grains from anther to stigma of the same flower or to another flower of the same plant. | It refers to the transfer of pollen grains from anther to stigma of flowers belonging to two different plants. |
| It is not necessary to use pollinators. | This transfer of pollen from one flower to another is achieved by agents like wind, water or animals. |
APPEARS IN
संबंधित प्रश्न
Match the following:
| Column A | Column B |
| (i) Stigma | (a) Neuron |
| (ii) Pepsin | (b) Carpel |
| (iii) Dendrites | (c) Protein |
| (d) Stamen |
Write the names of those parts of a flower which serve the same function as the following do in the animals :
(i) testis,
(ii) sperm,
(iii) ovary,
(iv) egg
Fill in the following blank with suitable word :
The ovule becomes a .......... after fertilisation.
What is meant by 'unisexual flowers' and 'bisexual flowers'? Give two examples of each.
The length of pollen tube depends on the distance between :
(a) pollen grain and upper surface of stigma
(b) pollen grain on upper surface of stigma and ovule
(c) pollen grain in anther and upper surface of stigma
(d) upper surface of stigma and lower part of style
The flask-shaped organ A at the centre of a flower is surrounded by a number of little stalks B having swollen tops which lie just inside the ring of petals.
(a) Name A. What are the various parts of A?
(b) Which part of A contains gametes?
(c) Name B. What is the swollen top of B known as?
(d) What does the swollen top of b contain?
(e) Out of A and B, which one is (i) male part, and (ii) female part of the flower?
Fill in the blank:
Seeds are formed from________.
Draw a diagram of the longitudinal section of a flower exhibiting germination of pollen on stigma and label (i) ovary, (ii) male germ-cell, (iii) female germ-cell and (iv) ovule on it.
In which part of the flower germination of pollen grains takes place?
The figure below shows the concept of double fertilization. Complete the flow chart showing the progress at each step:
