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प्रश्न
Give some examples of different modes of fertilisation in nature?
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उत्तर
There are two modes of fertilisation, i.e., external fertilisation as seen in case of fishes and frogs, and internal fertilisation that happens in humans, dogs, etc.
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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
The fusion of male and female gametes is termed as ______.
Fill in the following blank with suitable word :
The ovary of a flower becomes ....... after fertilisation.
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
Fill in the blank by selecting suitable word:
A flower bearing only male or female parts is known as __________ flower.
Fill in the blanks:
A stamen consists of ______ and ________.
State whether the following statement is true (T) or false (F):
Stamens make egg cells.
Identify A, B, C and D in the given diagram and write their names.
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
In the figure, the parts marked A, B and C are sequentially:
(A) Plumule, Radicle and Cotyledon
(B) Radicle, Plumule and Cotyledon
(C) Plumule, Cotyledon and Radicle
(D) Radicle, Cotyledon and Plumule
Draw a diagram of a pistil showing pollen tube growth into the ovule and label the following:
Pollen grain, male gamete, female gamete, ovary.
Fill in the blank by selecting suitable word:
Transfer of pollen grains from the anther to the stigma is known as______________.
The male reproductive part of a flower is ______.
The ovule of an angiosperm is technically equivalent to ______
Double fertilization is exhibited by ______
What is the structural unit of sexual reproduction in plant?
What are the agents for pollination?
Sexual maturation of reproductive tissues and organs are necessary link for reproduction. Elucidate.
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.
In male reproductive whorl of a flower the archesporial cells are formed by ______.
