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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
(i) Name the part marked 'A' in the diagram.
(ii) How dose 'A' reachese part 'B'?
(iii) State the importance of the part 'C'.
(iv) What happens to the part marked 'D' after fertilisation is over?
A student while observing an embryo of a pea seed in the laboratory listed various parts of the embryo as given below:
Testa, Tegmen, Radicle, Plumule, Micropyle, Cotyledon.
On examining the list the teacher remarked that only three parts are correct. Select three correct parts from the above list:
(a) Testa, Radicle, Cotyleddon
(b) Tegmen, Radicle, Micropyle
(c) Cotyledon, Plumule, Testa
(d) Radicle, Cotyledon, Plumule
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
Sketch the reproductive parts of a flower.
The process of fusion of the male and female gametes is called ______.
Where are a plant's sex organs located?
Where is the female gamete formed in flowering plants?
Fill in the following blank with suitable word :
Ovules contain ......... gametes of a plant.
What is seed?
Name the part of a seed which contains stored food.
Name the part of a seed which grows into root.
How does pollination occur?
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
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?
Put a tick mark (✓) against the correct alternative in the following statement
Reproductive whorls of a flower are:
Fill in the blanks:
A stamen consists of ______ and ________.
Find the odd-one out, giving reason:
Anther, pollen grain, ovule male gamete
What are the male and female gametes in a flowering plant?
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.
Distinguish between unisexual and bisexual flowers giving one example of each. Draw a diagram showing process of germination of pollen grains on stigma and label the following parts:
(a) Female germ cell
(b) Male germ cell
(c) Ovary
Identify the odd. Stigma, Style, Pollen, Ovary.
Sketch the labelled diagram.
Flower with its sexual reproductive organs.
Answer the following question.
How does suitable pollination lead to fertilization?
What is cleistogamy? Write one advantage and one disadvantage of it, to the plant.
Answer the following question.
List two agents of pollination?
__________ is present in unisexual flower.
Give scientific reason.
Fertilization in plants is called double fertilization.
In which part of the flower germination of pollen grains takes place?
How many middle layers are generally present in the wall of the anther lobes?
Conidia are formed endogenously while zoospores are formed endogenously.
Which among the following statements are true for sexual reproduction in flowering plants?
- It requires two types of gametes
- Fertilisation is a compulsory event
- It always results in formation of zygote
- Offspring formed are clones
In a bisexual flower inspite of the young stamens being removed artificially, the flower produces fruit. Provide a suitable explanation for the above situation.
Is the chromosome number of zygote, embryonal cells and adult of a particular organism always constant? How is the constancy maintained in these three stages?
Draw the diagram of a flower and label the four whorls. Write the names of gamete producing organs in the flower.
Sketch and label the essential and accessory whorls of flower.
What are the agents for pollination?
- Assertion: Primary endosperm nucleus is diploid.
- Reason: It is the product of double fertilisation.
