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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
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
The anther contains ______.
The fusion of male and female gametes is termed as ______.
Name the male part of the flower.
What is the function of a flower?
Fill in the following blank with suitable word :
The female organ of reproduction in the flower is the...........
Fill in the following blank with suitable word :
The.......... at the base of the carpel contains egg cells.
How do the insects help in cross-pollination?
What is meant by ‘unisexual flowers’?
How does pollination occur?
Describe the process of fertilisation in a flower with the help of labelled diagrams.
In the figure given alongside, the parts marked A, B and C are sequentially:
The part of a seed which grows and develops into root on germination is :
(a) cotyledon
(b) plumule
(c) follicle
(d) radicle
Fill in the blank by selecting suitable word:
A flower bearing only male or female parts is known as __________ flower.
What is a flower ? Draw a neat labelled diagram showing the L.S. of a typical flower.
Mention the function of Stigma.
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
Draw a diagram of the longitudinal section of a flower and label on it sepal, petal, ovary and stigma.
List any two differences between pollination and fertilization.
Fill in the blanks and rewrite the completed statements:
Lymph flows in _______________ direction.
Mention pollination types.
Differentiate between self-pollination and cross-pollination.
Find an odd one out.
In which part of the flower germination of pollen grains takes place?
Which of the following are the chemical components of the wall of pollen tube?
Antipodal cells are present towards the ______ in an anatropous ovule.
Pineapple fruit develops from ______.
The seed that contains the future plant is called the ______
In human beings, fertilization occurs in the ______
Length of pollen tube depends on the distance between ______
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
Give reason for the following:
Fertilization cannot take place in flowers if pollination does not occur.
Double fertilization is exhibited by ______
Sexual maturation of reproductive tissues and organs are necessary link for reproduction. Elucidate.
In male reproductive whorl of a flower the archesporial cells are formed by ______.
