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प्रश्न
How do the insects help in cross-pollination?
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उत्तर
When an insect sits on a flower, the pollens from the anther stick to their wings. The same insect when sits on another flower, the pollens from its wings stick to the stigma of that flower thereby affecting pollination.
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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
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
Where are the pollen grains produced?
Where is the male gamete formed in flowering plants?
Fill in the following blank with suitable word :
The ovary of a flower becomes ....... after fertilisation.
Fill in the following blank with suitable word :
The.......... at the base of the carpel contains egg cells.
Explain the terms 'self pollination'
(a) Identify A, B and C in the given diagram and write their functions.
(b) Mention the role of gamete and zygote in sexually reproducing organisms.
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.
Find the odd one out:
__________ is present in unisexual flower.
Give scientific reason.
Fertilization in plants is called double fertilization.
The ovule of an angiosperm is technically equivalent to ______
What would be the number of chromosomes in the cells of the aleurone layer in a plant species with 8 chromosomes in its synergids?
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
Double fertilization means ______.
What is the function of calyx?
- Assertion: Primary endosperm nucleus is diploid.
- Reason: It is the product of double fertilisation.
