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प्रश्न
Give scientific reason.
Flower is a structural unit of sexual reproduction in plants.
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उत्तर
Flower is structural unit of sexual reproduction in plants. It consists of four floral whorls as calyx, corolla, androecium and gynoecium; arranged in sequence from outside to inside. Androecium and gynoecium are called 'essential whorls' because they perform the function of reproduction whereas calyx and corolla are called as 'accessory whorls' because they are responsible for protection of inner whorls.
संबंधित प्रश्न
Match the following:
| Column A | Column B |
| (i) Stigma | (a) Neuron |
| (ii) Pepsin | (b) Carpel |
| (iii) Dendrites | (c) Protein |
| (d) Stamen |
Name the parts A, B and C shown in the following diagram and state one function of each.
Name and differentiate between the two modes of pollination in flowering plants.
Give one example of a unisexual flower.
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.
What is the function of a flower?
Fill in the following blank with suitable word :
Pollen grains contain ............ gametes of a plant.
Fill in the following blank with suitable word :
The male organ of reproduction in the flower is the.......... .
Explain the terms 'self pollination'
What is meant by 'unisexual flowers' and 'bisexual flowers'? Give two examples of each.
What changes take place in the flower after fertilisation which lead to the formation of seeds and fruit?
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
Which of the following statements are true for sexual reproduction in flowering plants?
(i) it requires two types of gametes
(ii) fertilisation is a compulsory event
(iii) it always results in the formation of zygote
(iv) offsprings formed are clones
(a) (i) and (iv)
(b) (i), (ii) and (iv)
(c) (i), (ii) and (iii)
(d) (ii), (iii) and (iv)
Fill in the blank by selecting suitable word:
A flower that bears both the male and the female parts is known as __________ flower.
Mention the function of Anther.
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.
Explain the process of fertilisation in flowers.
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
Draw a diagram of the longitudinal section of a flower and label on it sepal, petal, ovary and stigma.
Which of the following is not an unisexual flower?
a) Coconut
b) Papaya
c) Gulmohor
d) Maize
Mention pollination types.
Answer the following question.
How does suitable pollination lead to fertilization?
Accessory whorls : Calyx and corolla : : essential whorls : ______________
Pollen tube reaches the embryo sac via style.
Define.
Inflorescence
The male reproductive part of a flower is ______.
Which type of development is observed in male gametophytes of plants?
The 3-celled egg apparatus at the micropylar end comprises of ______
Conidia are formed endogenously while zoospores are formed endogenously.
The process of release of eggs from the ovary is called ______
In human beings, fertilization occurs in the ______
Pollen grains are produced by ______
Draw the diagram of a flower and label the four whorls. Write the names of gamete producing organs in the flower.
Double fertilization is exhibited by ______
Give any two examples of agents of pollination.
State the post-fertilisation changes that lead to fruit formation in plants.
