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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, the male organ is the stamen and the 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 stamens, 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
A student was asked to observe and identify the various parts of an embryo of a red kidney bean seed. He identified the parts and listed them as under:
I. Tegmen
II. Testa
III. Cotyledon
IV. Radicle
V. Plumule
The correctly identified parts among these are
(A) I, II and III
(B) II, III and IV
(C) III, IV and V
(D) I, III, IV and V
(i) Name the part marked 'A' in the diagram.
(ii) How dose 'A' reachese part 'B'?
(iii) State the importance of the part 'C'.
(iv) What happens to the part marked 'D' after fertilisation is over?
A student while observing an embryo of a pea seed in the laboratory listed various parts of the embryo as given below:
Testa, Tegmen, Radicle, Plumule, Micropyle, Cotyledon.
On examining the list the teacher remarked that only three parts are correct. Select three correct parts from the above list:
(a) Testa, Radicle, Cotyleddon
(b) Tegmen, Radicle, Micropyle
(c) Cotyledon, Plumule, Testa
(d) Radicle, Cotyledon, Plumule
Sketch the reproductive parts of a flower.
State the name of the functional unit concerned with sexual reproduction.
Name the part made up of the stigma, style and ovary.
What is the name of female part of a flower?
What is the name of female organ of a flower (other than carpel)?
Fill in the following blank with suitable word :
Flowering plants reproduce by ...........method of reproduction.
Draw a neat sketch of the carpel of a flower. Mark in it stigma, style and ovary.
Explain the terms 'self pollination'
Give some examples of different modes of fertilisation in nature?
Describe the process of fertilisation in a flower with the help of labelled diagrams.
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.
Which of the following statements are true for sexual reproduction in flowering plants?
(i) it requires two types of gametes
(ii) fertilisation is a compulsory event
(iii) it always results in the formation of zygote
(iv) offsprings formed are clones
(a) (i) and (iv)
(b) (i), (ii) and (iv)
(c) (i), (ii) and (iii)
(d) (ii), (iii) and (iv)
The part of a seed which grows and develops into root on germination is :
(a) cotyledon
(b) plumule
(c) follicle
(d) radicle
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?
Put a tick mark (✓) against the correct alternative in the following statement
Pollen is produced in the:
Fill in the blank by selecting suitable word:
A flower bearing only male or female parts is known as __________ flower.
State whether the following statement is true (T) or false (F):
Flowers which possess stamens and carpel are called unisexual.
Draw a labelled diagram of a bisexual flower.
What is phototropism?
List any two differences between pollination and fertilization.
Differentiate between self-pollination and cross-pollination.
Find an odd one out.
Draw a neat and labelled diagram.
Double fertilization in angiosperms
Match the following
| 1. | Petal | Opuntia |
| 2. | Fern | Chrysanthemum |
| 3. | Phylloclade | Attracts insect |
| 4. | Hooks | Spore |
| 5. | Sucker | Bignonia |
Write the events involved in the sexual reproduction of a flowering plant.
Discuss the first event and write the types.
Where does the endothecium layer of anther lobes is present?
The anther wall consists of four wall layers where ______
Which of the following are the chemical components of the wall of pollen tube?
Which type of development is observed in male gametophytes of plants?
The flower of the Hibiscus plant is ______
In a bisexual flower inspite of the young stamens being removed artificially, the flower produces fruit. Provide a suitable explanation for the above situation.
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
