Advertisements
Advertisements
प्रश्न
Give scientific reason.
Flower is a structural unit of sexual reproduction in plants.
Advertisements
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
In the following diagram showing the structure of embryo of a dicot seed, what are the parts marked I, II and III sequentially?
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
Explain what you understand by sexual reproduction.
How does the process of fertilisation take place in flowers?
The reproductive part of a plant is the ______.
The process of fusion of the male and female gametes is called ______.
How do the insects help in cross-pollination?
Name the part of a seed which contains stored food.
Name the part of a seed which grows into root.
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?
Multiple choice question. Tick (✓) the correct choice:
The male gamete is present inside the which germinates.
- the style
- the stigma
- the anther
- the ovary
State whether the following statement is true (T) or false (F):
Flowers which possess stamens and carpel are called unisexual.
Mention the function of Flower.
Mention the function of Anther.
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.
Identify A, B, C and D in the given diagram and write their names.
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
What is phototropism?
Identify the odd. Stigma, Style, Pollen, Ovary.
Answer the following question.
How does suitable pollination lead to fertilization?
Answer the following question.
List two agents of pollination?
Bisexual : Hibiscus : : Unisexual : ___________
Match the following
| 1. | Petal | Opuntia |
| 2. | Fern | Chrysanthemum |
| 3. | Phylloclade | Attracts insect |
| 4. | Hooks | Spore |
| 5. | Sucker | Bignonia |
Write the events involved in the sexual reproduction of a flowering plant.
a. Discuss the first event and write the types.
b. Mention the advantages and the disadvantages of that event.
Where does the endothecium layer of anther lobes is present?
The 3-celled egg apparatus at the micropylar end comprises of ______
What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its roots tip cells?
What would be the number of chromosomes in the cells of the aleurone layer in a plant species with 8 chromosomes in its synergids?
The seed that contains the future plant is called the ______
The process of release of eggs from the ovary is called ______
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
State the number of sets of chromosomes present in a zygote.
Double fertilization means ______.
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.
The pollen tube usually enters the embryo sac ______.
