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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
Name the parts labelled as A, B, C and D in the diagram given below:-
State significance of pollination.
Mention the changes a flower undergoes after fertilisation.
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
Name the part made up of the stigma, style and ovary.
Where are a plant's sex organs located?
What is made in ovary of a flower?
Name the part of a seed which contains stored food.
What is pollination? How does pollination occur?
In what ways is fertilisation in a plant similar to fertilisation in a human?
In what ways is fertilisation in a plant different from fertilisation in a human?
Mention the function of Stigma.
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.
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.
Identify the odd. Stigma, Style, Pollen, Ovary.
Sketch the labeled diagram:
Flower with its sexual reproductive organs
Calyx : Sepals : : Corolla : ________________
Pollen grains from anther are transferred to the stigma.
Write the events involved in the sexual reproduction of a flowering plant.
Discuss the first event and write the types.
