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प्रश्न
Explain sexual reproduction in plants.
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उत्तर
- In sexually reproducing plants, flowers function as the reproductive organs.
- In flowers, male organ is the stamen and female organ is the carpel.
- Flowers which have both the male and female organs i.e. stamens and carpels are called bisexual flowers whereas flowers which have either male or female organs are called unisexual.
- Male gametes called pollen grains are produced by stamen, and carpels produce female gametes called ovules or egg cells inside ovaries.
- Fertilization takes place in the ovule where the egg cell and pollen grain fuse.
- This fertilized egg cell later develops into an embryo and the entire ovule gets converted into a seed.
- Under favourable conditions, the seed germinates to give rise to a new plant.
APPEARS IN
संबंधित प्रश्न
What is pollination?
Name the parts labelled as A, B, C and D in the diagram given below:
You are asked by your teacher to study the different parts of an embryo of a gram seed. Given below are the steps to be followed for the experiment:
I. Soak the gram seeds in plain water and keep them overnight.
II. Cut open a soaked seed and observe its different parts.
III. Take some dry gram seeds in a petri dish.
IV. Drain the excess water.
V. Cover the soaked seeds with a wet cotton cloth and leave them for a day.
The correct sequence of these steps is :
(A) III, I, V, IV, II
(B) III, I, II, IV, V
(C) III, IV, V, I, II
(D) III, I, IV, V, II
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
State the function of flowers in the flowering plants.
The anther contains ______.
The process of fusion of the male and female gametes is called ______.
Name the male part of the flower.
Fill in the following blank with suitable word :
Ovules contain ......... gametes of a plant.
Fill in the following blank with suitable word :
The ovule becomes a .......... after fertilisation.
Fill in the following blank with suitable word :
Flowering plants reproduce by ...........method of reproduction.
Fill in the following blank with suitable word :
The.......... at the base of the carpel contains egg cells.
How do the insects help in cross-pollination?
What is pollination? How does pollination occur?
Which of the following is the correct sequence of events of sexual reproduction in a flower?
(a) pollination, fertilisation, seed, embryo
(b) seed, embryo, fertilisation, pollination
(c) pollination, fertilisation, embryo, seed
(d) embryo, seed, pollination, fertilisation
When an insect sits on the flower of a plant then some particles A present in the top of little stalks in the flower attach to its body hair. When this insect now sits on the flower of another similar plant, then particles A attached to the hair of insect are put on the top of a flask-shaped organ at the centre of flower. The particle A grows a long tube b from the top of flask-shaped organ through which C moves down and reaches the bottom part of flask-shaped organ. Here C fuses with the nucleus of d contained in structure E. the fusion of C and D forms a new cell f which grows and develops into a seed of the plant.
(a) What are particles A? What is the process of transferring A from one flower to another flower of similar plant by the insect known as?
(b) What is the name of tube B?
(c) What is C which moves down through the tube B?
(d) Name D and E.
(e) What is F?
Fill in the blank:
Seeds are formed from________.
Mention the function of Flower.
Mention the function of Anther.
You have to perform the experiment, "To identify the different parts of an embryo of a gram seed." Describe the procedure that you would follow.
A student is asked to study the different parts of an embryo of pea seeds. Given below are the essential steps for the experiment :
(I) Soak the pea seeds in plain water and keep them overnight.
(II) Cut open the soaked seed and observe its different parts.
(III) Take some pea seeds in a petri dish.
(IV) 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) III, I, IV, II
(B) III, IV, I, II
(C) III, I, II, IV
(D) III, II, I, IV
Describe an activity to demonstrate phototropism.
Find the odd one out:
Bisexual : Hibiscus : : Unisexual : ___________
Pollen tube reaches the embryo sac via style.
Write the functions of sepals
Observe the figure below. Write functions of the labelled parts.
Where does the endothecium layer of anther lobes is present?
In which of the following manner the arrangement of megaspores in a tetrad is observed in angiosperms?
In a flowering plant, archesporium gives rise to ______.
In human beings, fertilization occurs in the ______
Pollen grains are produced by ______
Which out of the following processes does not lead to the formation of clones.
Sketch and label the essential and accessory whorls of flower.
What is the structural unit of sexual reproduction in plant?
What is the function of calyx?
