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प्रश्न
Distinguish between unisexual and bisexual flowers giving one example of each. Draw a diagram showing process of germination of pollen grains on stigma and label the following parts:
(a) Female germ cell
(b) Male germ cell
(c) Ovary
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उत्तर
|
Unisexual Flower |
Bisexual Flower |
|
The flower has either stamen or pistil only are called unisexual flowers. |
The flower has both stamen and pistil are called bisexual flowers. |
|
Example: Papaya |
Example: Hibiscus |
Diagram showing germination of pollen grain on stigma:
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संबंधित प्रश्न
Name the parts A, B and C shown in the diagram and write their functions.
Name and differentiate between the two modes of pollination in flowering plants.
State the function of flowers in the flowering plants.
State the name of the functional unit concerned with sexual reproduction.
Draw a neat sketch of the carpel of a flower. Mark in it stigma, style and ovary.
In tobacco plant, the male gametes have 24 chromosomes.
What is the number of chromosomes in the female gamete?
| When an insect sits on the flower of a plant then somene 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. |
- 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?
- What is the name of tube B?
- What is C which moves down through the tube B?
- Name D and E.
- What is F?
Draw a diagram of the longitudinal section of a flower and label on it sepal, petal, ovary and stigma.
Find an odd one out.
Generally, in a pollen tube, which of the following moves to the tip of the tube?
