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प्रश्न
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?
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उत्तर
(a) A represents pollen grains. The process of transferring pollen grains from one flower to another flower of the similar plant by insects is known as cross pollination.
(b) B represents the pollen tube.
(c) C is the male gamete which moves down through the pollen tube (B).
(d) D is the female gamete (or egg). The structure E represents the ovule.
(e) F is the zygote.
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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
A flower may have either male or female reproductive parts. Such a flower is called ______.
How does the process of fertilisation take place in flowers?
Name the part of a seed which grows into root.
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)
In the figure given alongside, the parts marked A, B and C are sequentially :
(a) cotyledon, plumule and radicle
(b) plumule, radicle and cotyledon
(c) plumule, cotyledon and radicle
(d) radicle, cotyledon and plumule
Fill in the blanks:
A stamen consists of ______ and ________.
Give one example each of unisexual and bisexual flowers. Differentiate between the two types of pollination that occur in flowers. What happens when a pollen lands on a suitable stigma? Write about the events that occur till the seed formation in the ovary.
Define.
Inflorescence
Give scientific reason.
Flower is a structural unit of sexual reproduction in plants.
Match the following
| 1. | Petal | Opuntia |
| 2. | Fern | Chrysanthemum |
| 3. | Phylloclade | Attracts insect |
| 4. | Hooks | Spore |
| 5. | Sucker | Bignonia |
Where does the endothecium layer of anther lobes is present?
The anther wall consists of four wall layers where ______
The ovule of an angiosperm is technically equivalent to ______
What would be the number of chromosomes in the cells of the aleurone layer in a plant species with 8 chromosomes in its synergids?
Which out of the following processes does not lead to the formation of clones.
The pollen tube usually enters the embryo sac ______.
