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प्रश्न
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
Why cannot fertilization take place in flowers if pollination does not occur?
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उत्तर
In flowering plants, male gametes are produced in the pollen grains inside the anther. Pollination brings the pollen grains having male gametes from the anther to the stigma. Upon successful arrival of pollen grains on the stigma, a pollen tube is formed where they take male gamete to the female gamete or egg present in the ovule for fertilisation. So, if pollination does not occur, fertilisation will also not take place.
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संबंधित प्रश्न
What is pollination?
In the following diagram showing the structure of embryo of a dicot seed, what are the parts marked I, II and III sequentially?
Name the parts labelled as A, B, C and D in the diagram given below:
The fusion of male and female gametes is termed as ______.
Sketch the reproductive parts of a flower.
State the name of the functional unit concerned with sexual reproduction.
Where are the pollen grains produced?
Explain the term 'fertilisation'.
(a) Draw a neat diagram of a flower showing its various parts. In this diagram mark stem, receptacle, sepals, petals, stamen and carpel.
(b) What name is given to (i) all the petals of a flower, and (ii) all the sepals of a flower?
(c) What are (i) stamen, and (ii) carpel, in a flower?
(d) What is the other name of carpel of a flower?
(e) What is the name of yellow powdery substance present in the anther of a flower?
Which of the following statements are true for flowers?
(i) Flowers are always bisexual.
(ii) They contain sexual reproductive organs.
(iii) They are produced in all groups of plants.
(iv) after fertilization they give rise to fruits.
The correct sequence of reproductive stages occurring in flowering plants is ______
Fill in the blank:
Seeds are formed from________.
State whether the following statement is true (T) or false (F):
Flowers which possess stamens and carpel are called unisexual.
What is cleistogamy? Write one advantage and one disadvantage of it, to the plant.
Observe the figure below. Write functions of the labelled parts.
Match the following
| 1. | Petal | Opuntia |
| 2. | Fern | Chrysanthemum |
| 3. | Phylloclade | Attracts insect |
| 4. | Hooks | Spore |
| 5. | Sucker | Bignonia |
Which type of development is observed in male gametophytes of plants?
In human beings, fertilization occurs in the ______
Complete the table
| Carly x | ______ | ______ |
| ______ | petal | attract insects |
| Androecium | ______ | Male reproductive part |
| ______ | ______ | Female reproductive part. |
The pollen tube usually enters the embryo sac ______.
