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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
How does fertilisation occur in flowers? Name the parts of the flower that develop into (i) seed, and (ii) fruit after fertilisation.
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
How is the process of pollination different from fertilization?
The process of fusion of the male and female gametes is called ______.
State the name of the functional unit concerned with sexual reproduction.
Fill in the following blank with suitable word :
Pollen grains contain ............ gametes of a plant.
What type of plants reproduce by sexual reproduction method?
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?
In a bisexual flower, inspite of the young stamens being removed artificially, the flower produces fruit. Explain.
Put a tick mark (✓) against the correct alternative in the following statement
Pollen is produced in the:
Put a tick mark (✓) against the correct alternative in the following statement
Reproductive whorls of a flower are:
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
Draw a diagram of the longitudinal section of a flower and label on it sepal, petal, ovary and stigma.
List any two differences between pollination and fertilization.
Prepare a slogan for campaign against female foeticide.
Mention pollination types.
What is meant by pollination?
Find the odd one out:
Bisexual : Hibiscus : : Unisexual : ___________
Pollen tube reaches the embryo sac via style.
What does germination mean?
Write the functions of sepals
Distinguish between self-pollination and cross-pollination.
Draw a neat and labelled diagram.
Double fertilization in angiosperms
Observe the figure below. Write functions of the labelled parts.
In which of the following manner the arrangement of megaspores in a tetrad is observed in angiosperms?
Which of the following is the outermost protective layer of anther?
The seed that contains the future plant is called the ______
In human beings, fertilization occurs in the ______
Complete the table
| Carly x | ______ | ______ |
| ______ | petal | attract insects |
| Androecium | ______ | Male reproductive part |
| ______ | ______ | Female reproductive part. |
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
Where is the zygote located in the flower after fertilization?
Double fertilization is essential for formation of ______.
What is the function of calyx?
Triple fusion involves ______.
Type of sexual reproduction is ______.
State the post-fertilisation changes that lead to fruit formation in plants.
