Advertisements
Advertisements
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
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
A student was asked to observe and identify the various parts of an embryo of a red kidney bean seed. He identified the parts and listed them as under:
I. Tegmen
II. Testa
III. Cotyledon
IV. Radicle
V. Plumule
The correctly identified parts among these are
(A) I, II and III
(B) II, III and IV
(C) III, IV and V
(D) I, III, IV and V
What is pollination?
Name the parts labelled as A, B, C and D in the diagram given below:
The anther contains ______.
State the name of the functional unit concerned with sexual reproduction.
Fill in the following blank with suitable word :
The ovary of a flower becomes ....... after fertilisation.
How is the process of pollination different from fertilization?
When an insect sits on the flower of a plant then some particles A present in the top of little stalks in the flower attach to its body hair. When this insect now sits on the flower of another similar plant, then particles A attached to the hair of insect are put on the top of a flask-shaped organ at the centre of flower. The particle A grows a long tube b from the top of flask-shaped organ through which C moves down and reaches the bottom part of flask-shaped organ. Here C fuses with the nucleus of d contained in structure E. the fusion of C and D forms a new cell f which grows and develops into a seed of the plant.
(a) What are particles A? What is the process of transferring A from one flower to another flower of similar plant by the insect known as?
(b) What is the name of tube B?
(c) What is C which moves down through the tube B?
(d) Name D and E.
(e) What is F?
Fill in the blank by selecting suitable word:
A flower that bears both the male and the female parts is known as __________ flower.
What part is played by stamens and carpels in reproduction?
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.
The essential parts of a flower are ______.
In which of the following manner the arrangement of megaspores in a tetrad is observed in angiosperms?
Pollen grains are produced by ______
In a bisexual flower inspite of the young stamens being removed artificially, the flower produces fruit. Provide a suitable explanation for the above situation.
Double fertilization is exhibited by ______
Double fertilization means ______.
The figure below shows the concept of double fertilization. Complete the flow chart showing the progress at each step:
In flowering plants, the pollen grains are transferred to stigma by pollination but the female germ cells are present in the ovary.
Explain with the help of a labelled diagram (only concerned parts), how the male germ cell reaches the ovary.
