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प्रश्न
Explain sexual reproduction in plants.
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उत्तर
- In sexually reproducing plants, flowers function as the reproductive organs.
- In flowers, the male organ is the stamen and the female organ is the carpel.
- Flowers which have both the male and female organs, i.e. stamens and carpels, are called bisexual flowers, whereas flowers which have either male or female organs are called unisexual.
- Male gametes, called pollen grains, are produced by stamens, and carpels produce female gametes, called ovules or egg cells, inside ovaries.
- Fertilization takes place in the ovule where the egg cell and pollen grain fuse.
- This fertilized egg cell later develops into an embryo and the entire ovule gets converted into a seed.
- Under favourable conditions, the seed germinates to give rise to a new plant.
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संबंधित प्रश्न
A student while observing an embryo of a pea seed in the laboratory listed various parts of the embryo as given below:
Testa, Tegmen, Radicle, Plumule, Micropyle, Cotyledon.
On examining the list the teacher remarked that only three parts are correct. Select three correct parts from the above list:
(a) Testa, Radicle, Cotyleddon
(b) Tegmen, Radicle, Micropyle
(c) Cotyledon, Plumule, Testa
(d) Radicle, Cotyledon, Plumule
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
Write the names of those parts of a flower which serve the same function as the following do in the animals :
(i) testis,
(ii) sperm,
(iii) ovary,
(iv) egg
State the function of flowers in the flowering plants.
Name the male part of the flower.
What is the name of female organ of a flower (other than carpel)?
Fill in the following blank with suitable word :
The ovary of a flower becomes ....... after fertilisation.
Explain the terms 'self pollination'
Explain the term 'fertilisation'.
Describe the process of fertilisation in a flower with the help of labelled diagrams.
The part of a seed which grows and develops into root on germination is :
(a) cotyledon
(b) plumule
(c) follicle
(d) radicle
In a bisexual flower, inspite of the young stamens being removed artificially, the flower produces fruit. Explain.
Fill in the blank by selecting suitable word:
A flower that bears both the male and the female parts is known as __________ flower.
Multiple choice question. Tick (✓) the correct choice:
The male gamete is present inside the which germinates.
- the style
- the stigma
- the anther
- the ovary
Mention the function of Flower.
The students of a class were asked by the teacher to study the different parts of an embryo of an angiosperm. Given below are the essential steps for the experiment :
A. Soak the seeds in plain water and keep them overnight.
B. Cut open the soaked seed and observe its different parts.
C. Take some healthy seeds in a petri-dish.
D. 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) C, A, D, B
(b) C, D, A, B
(c) A, C, D, B
(d) A, C, B, D
(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.
Draw a diagram of a pistil showing pollen tube growth into the ovule and label the following:
Pollen grain, male gamete, female gamete, ovary.
Describe an activity to demonstrate phototropism.
Draw a diagram of the longitudinal section of a flower and label the following parts.
A student is observing the temporary mount of a leaf peel under a microscope. Draw a labelled diagram of the structure of stomata as seen under the microscope
Find the odd one out:
Accessory whorls : Calyx and corolla : : essential whorls : ______________
Pollen tube reaches the embryo sac via style.
Give scientific reason.
Fertilization in plants is called double fertilization.
Observe the figure below. Write functions of the labelled parts.
Match the following
| 1. | Petal | Opuntia |
| 2. | Fern | Chrysanthemum |
| 3. | Phylloclade | Attracts insect |
| 4. | Hooks | Spore |
| 5. | Sucker | Bignonia |
What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its roots tip cells?
The seed that contains the future plant is called the ______
Which out of the following processes does not lead to the formation of clones.
Where is the zygote located in the flower after fertilization?
Trace the path a male gamete takes to fertilise a female gamete after being released from the penis.
State the number of sets of chromosomes present in a zygote.
In a plant flower the female whorl is ______.
What is the function of calyx?
Given below is a diagram of a germinating seed. Label the parts that:
- gives rise to future shoot.
- gives rise to future root system.
- stores food.
- Assertion: Primary endosperm nucleus is diploid.
- Reason: It is the product of double fertilisation.
