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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
Name the parts labelled as A, B, C and D in the diagram given below:-
State the function of flowers in the flowering plants.
State the name of the functional unit concerned with sexual reproduction.
What is the name of female organ of a flower (other than carpel)?
What is made in ovary of a flower?
Give some examples of different modes of fertilisation in nature?
Name the part of a seed which contains stored food.
Put a tick mark (✓) against the correct alternative in the following statement
Reproductive whorls of a flower are:
State whether the following statement is true (T) or false (F):
Flowers which possess stamens and carpel are called unisexual.
The students of a class were asked by the teacher to study the different parts of an embryo of an angiosperm. Given below are the essential steps for the experiment :
A. Soak the seeds in plain water and keep them overnight.
B. Cut open the soaked seed and observe its different parts.
C. Take some healthy seeds in a petri-dish.
D. Drain the excess water, cover the seeds with a wet cotton cloth and leave them as it is for a day.
The correct sequence of these steps is
(a) C, A, D, B
(b) C, D, A, B
(c) A, C, D, B
(d) A, C, B, D
In the figure, the parts marked A, B and C are sequentially:
(A) Plumule, Radicle and Cotyledon
(B) Radicle, Plumule and Cotyledon
(C) Plumule, Cotyledon and Radicle
(D) Radicle, Cotyledon and Plumule
Answer the following question.
How does suitable pollination lead to fertilization?
__________ is present in unisexual flower.
Accessory whorls : Calyx and corolla : : essential whorls : ______________
Draw a neat and labelled diagram.
Double fertilization in angiosperms
In which of the following manner the arrangement of megaspores in a tetrad is observed in angiosperms?
How many middle layers are generally present in the wall of the anther lobes?
Variations occur as a result of ______
Complete the table
| Carly x | ______ | ______ |
| ______ | petal | attract insects |
| Androecium | ______ | Male reproductive part |
| ______ | ______ | Female reproductive part. |
In flowering plants, the pollen grains are transferred to stigma by pollination but the female germ cells are present in the ovary.
Explain with the help of a labelled diagram (only concerned parts), how the male germ cell reaches the ovary.
