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प्रश्न
(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.
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उत्तर
(a) A - Stigma, Function - The stigma is a sticky surface where the pollen lands and later germinates
B - Pollen tube, Function- It carries the pollen to the egg cell for fertilization
C - Egg cell, Function- It fuses with the male gamete and leads to the formation of zygote.
(b) Role of gametes- The gametes play an important role in the sexually reproducing organisms as they carry the entire genetic information of the organism. These gametes upon fusion result in the formation of zygote, which develops into a new individual. Any deformation in the gametes will lead to the deformity in the newly formed offspring.
Role of zygote- Zygote is the diploid cell formed by the fusion of male and female gametes during fertilization in sexual reproduction. Zygote is the first stage in the development process of an organism and it contains all the genetic information of both the parents, essential for the growth of the new organism.
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संबंधित प्रश्न
How does fertilisation occur in flowers? Name the parts of the flower that develop into (i) seed, and (ii) fruit after fertilisation.
Name the swollen lower part of the carpel.
Give some examples of different modes of fertilisation in nature?
One of the following occurs in the reproductive system of flowering plants as well as that of humans. This is :
(a) vas deferens
(b) anther
(c) ovary
(d) style
Put a tick mark (✓) against the correct alternative in the following statement
Pollen is produced in the:
What is a flower ? Draw a neat labelled diagram showing the L.S. of a typical flower.
Fill in the blanks:
A carpel consists of ________ , ________ and ________.
Write one main difference between asexual and sexual mode of reproduction. Which species is likely to have comparatively better chances of survival – the one reproducing asexually or the one reproducing sexually? Give reason to justify your answer.
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
How many middle layers are generally present in the wall of the anther lobes?
