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प्रश्न
Distinguish between self-pollination and cross-pollination.
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उत्तर
In self-pollination, only one or two flowers borne on the same plant are involved, whereas in cross-pollination two flowers borne on two plants of same species are involved.
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संबंधित प्रश्न
Match the following:
| Column A | Column B |
| (i) Stigma | (a) Neuron |
| (ii) Pepsin | (b) Carpel |
| (iii) Dendrites | (c) Protein |
| (d) Stamen |
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
What is pollination?
Name the parts labelled as A, B, C and D in the diagram given below:
Give one example of a unisexual flower.
Mention the changes a flower undergoes after fertilisation.
State the function of flowers in the flowering plants.
The anther contains ______.
Sketch the reproductive parts of a flower.
Name the swollen lower part of the carpel.
Fill in the following blank with suitable word :
Pollen grains contain ............ gametes of a plant.
Fill in the following blank with suitable word :
The ovary of a flower becomes ....... after fertilisation.
Explain the terms 'cross-pollination'?
How do the insects help in cross-pollination?
In tobacco plant, the male gametes have 24 chromosomes.
What is the number of chromosomes in the zygote?
What is pollination? How does pollination occur?
The length of pollen tube depends on the distance between :
(a) pollen grain and upper surface of stigma
(b) pollen grain on upper surface of stigma and ovule
(c) pollen grain in anther and upper surface of stigma
(d) upper surface of stigma and lower part of style
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.
State whether the following statement is true (T) or false (F):
Stamens make egg cells.
(a) Identify A, B and C in the given diagram and write their functions.
(b) Mention the role of gamete and zygote in sexually reproducing organisms.
“Cell division is a type of reproduction in unicellular organism.” Justify.
Draw a diagram of a pistil showing pollen tube growth into the ovule and label the following:
Pollen grain, male gamete, female gamete, ovary.
Identify the odd. Stigma, Style, Pollen, Ovary.
Draw a diagram of the longitudinal section of a flower and label the following parts.
Find an odd one out.
Calyx : Sepals : : Corolla : ________________
Write the functions of sepals
Draw a neat and labelled diagram.
Double fertilization in angiosperms
Write the events involved in the sexual reproduction of a flowering plant.
Discuss the first event and write the types.
The anther wall consists of four wall layers where ______
In which of the following manner the arrangement of megaspores in a tetrad is observed in angiosperms?
Complete the table
| Carly x | ______ | ______ |
| ______ | petal | attract insects |
| Androecium | ______ | Male reproductive part |
| ______ | ______ | Female reproductive part. |
Which among the following statements are true for sexual reproduction in flowering plants?
- It requires two types of gametes
- Fertilisation is a compulsory event
- It always results in formation of zygote
- Offspring formed are clones
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
Double fertilization means ______.
Sketch and label the essential and accessory whorls of flower.
State the post-fertilisation changes that lead to fruit formation in plants.
In male reproductive whorl of a flower the archesporial cells are formed by ______.
