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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
A student has to perform the experiment "To identify the different parts of an embryo of a dicot seed." Select from the following an appropriate group of seeds:
(a) Pea, gram, wheat
(b) Red kidney bean, maize, gram
(c) Maize, wheat, red kidney bean
(d) Red kidney bean, pea, gram
A student identified the various parts of an embryo of a gram seed and listed them as given below :
(I) Testa
(II) Plumule
(III) Radicle
(IV) Cotyledon
(V) Tegmen
Out of these the actual parts of the embryo are :
(A) I, II, III
(B) II, III, IV
(C) III, IV, V
(D) II, IV, V
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
Mature ovary forms the ______.
State the name of the functional unit concerned with sexual reproduction.
Name the swollen lower part of the carpel.
What is the function of a flower?
Fill in the following blank with suitable word :
Flowering plants reproduce by ...........method of reproduction.
What is made in anther of a flower?
What is made in ovary of a flower?
Explain the term 'fertilisation'.
Give some examples of different modes of fertilisation in nature?
Name the part of a seed which contains stored food.
Name the part of a seed which grows into root.
Describe the process of fertilisation in a flower with the help of labelled diagrams.
The flask-shaped organ A at the centre of a flower is surrounded by a number of little stalks B having swollen tops which lie just inside the ring of petals.
(a) Name A. What are the various parts of A?
(b) Which part of A contains gametes?
(c) Name B. What is the swollen top of B known as?
(d) What does the swollen top of b contain?
(e) Out of A and B, which one is (i) male part, and (ii) female part of the flower?
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?
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
What is phototropism?
Which of the following is not an unisexual flower?
a) Coconut
b) Papaya
c) Gulmohor
d) Maize
Draw a diagram of the longitudinal section of a flower and label the following parts.
Answer the following question.
List two agents of pollination?
Find an odd one out.
Pollen grains from anther are transferred to the stigma.
In which of the following manner the arrangement of megaspores in a tetrad is observed in angiosperms?
Identify the female gametophyte in angiosperms.
What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its roots tip cells?
Flowers showing ornithophily show few characteristic like ______.
Pineapple fruit develops from ______.
Conidia are formed endogenously while zoospores are formed endogenously.
The seed that contains the future plant is called the ______
The process of release of eggs from the ovary is called ______
Which among the following statements are true for unisexual flowers?
- They possess both stamen and pistil
- They possess either stamen or pistil
- They exhibit cross pollination
- Unisexual flowers possessing only stamens cannot produce fruits
Where is the zygote located in the flower after fertilization?
Sketch and label the essential and accessory whorls of flower.
In a plant flower the female whorl is ______.
