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प्रश्न
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
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उत्तर
(b) pollen grains on upper surface of stigma and ovule.
Pollen grains land on the surface of the stigma. Hence, the pollen tube is formed so that the pollens can reach the ovules present in the ovary.
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संबंधित प्रश्न
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 ______.
Fill in the following blank with suitable word :
Pollen grains contain ............ gametes of a plant.
Fill in the following blank with suitable word :
The term used to refer to the transfer of pollen from the stamen of one flower to the carpel of another flower of the same species is...........
Explain the terms 'self pollination'
Explain the terms 'cross-pollination'?
In tobacco plant, the male gametes have 24 chromosomes.
What is the number of chromosomes in the zygote?
Which of the following is the correct sequence of events of sexual reproduction in a flower?
(a) pollination, fertilisation, seed, embryo
(b) seed, embryo, fertilisation, pollination
(c) pollination, fertilisation, embryo, seed
(d) embryo, seed, pollination, fertilisation
The correct sequence of reproductive stages occurring in flowering plants is ______.
Fill in the blank by selecting suitable word:
A flower bearing only male or female parts is known as __________ flower.
Multiple choice question. Tick (✓) the correct choice:
Unisexual flowers are found in
- mulberry
- mustard
- pea
- sunflower
Draw a diagram of the longitudinal section of a flower exhibiting germination of pollen on stigma and label (i) ovary, (ii) male germ-cell, (iii) female germ-cell and (iv) ovule on it.
Which of the following is not an unisexual flower?
a) Coconut
b) Papaya
c) Gulmohor
d) Maize
Identify the odd. Stigma, Style, Pollen, Ovary.
Fill in the blank by selecting suitable word:
Transfer of pollen grains from the anther to the stigma is known as______________.
Mention pollination types.
Pollen grains from anther are transferred to the stigma.
The anther wall consists of four wall layers where ______
Where is the zygote located in the flower after fertilization?
Draw the diagram of a flower and label the four whorls. Write the names of gamete producing organs in the flower.
