Reproduction in Plants
Pollen is produced in the :
- Filament
- Style
- Pistil
- Anther
Answer
Anther
Reason — The anther consists of four sac-like structures that produce pollen for pollination.
Reproductive whorls of a flower are:
- Stamens and carpels
- Sepals and petals
- Sepals and stamens
- Petals and carpels
Answer
Stamens and Carpels
Reason — Stamens are the male reproductive parts of the flower.
Carpels are the female reproductive parts of the flower.
Grafting is a method of :
- Artificial vegetative propagation
- Sexual reproduction
- Artificial pollination
- Cross-pollination
Answer
Artificial vegetative propagation
Reason — Grafting is a process of joining two plants together to grow as one and is one of the methods of Artificial vegetative propagation.
Fill in the blanks by selecting suitable words:
(unisexual, fertilisation, fruit, stamen, anther, bisexual, pollination, seed, ovary)
(a) A flower that bears both the male and the female parts is known as ............... flower.
(b) A flower bearing only male or female parts is known as ............... flower.
(c) Transfer of pollen grains from the anther to the stigma is known as ...............
(d) Fusion of male cell with female cell is called ...............
(e) The ovule develops into a ...............
(f) The ovary of the flower develops into a ...............
Answer
(i) A flower that bears both the male and the female parts is known as bisexual flower.
(ii) A flower bearing only male or female parts is known as unisexual flower.
(iii) Transfer of pollen grains from the anther to the stigma is known as pollination.
(iv) Fusion of male cell with female cell is called fertilization.
(v) The ovule develops into a seed.
(vi) The ovary of the flower develops into a fruit.
Name the flower part that:
(a) develops into a fruit
(b) develops into a seed
(c) produces pollen grains
(d) attracts insects for pollination
(e) connects stigma to the ovary
Answer
(a) develops into a fruit — Ovary
(b) develops into a seed — Ovule
(c) produces pollen grains — Anther
(d) attracts insects for pollination — Petals
(e) connects stigma to the ovary — Style
Define Vegetative reproduction
Answer
Reproduction in plants wherein a new plant can arise from a vegetative part such as root, stem or leaf without the help of any reproductive organ is called vegetative reproduction.
Define Pollination
Answer
Pollination is the process in which the pollen grains from the anthers are transferred to the stigma of a flower of the same species.
Define Grafting
Answer
Grafting is a propagation technique where tissues from one plant (the scion) are inserted into or onto the tissues of another plant (the rootstock) so that they unite and continue growing together.
Define Micro-propagation
Answer
Micropropagation is the process of rapid propagation of plants by tissue culture techniques.
Define Fertilization
Answer
The process of fusion of male and female gametes to form a zygote is called Fertilization.
Write two ways in which pollination may occur in plants.
Answer
Two ways in which pollination may occur in plants are —
- Self-pollination
- Cross-pollination
Give two features of flowers which favour pollination by insects.
Answer
Two features of flowers which favour pollination by insects are —
- These flowers are large with coloured petals, to attract insects.
- These are scented so that insects locate the flowers by the smell.
State two characteristics of flowers in which pollination occurs by wind.
Answer
Two characteristics of flowers in which pollination occurs by wind are —
- They are usually small and are of dull colours.
- They generally have long anthers protruding out of the flowers so that pollen grains may get blown off easily.
Name the 5 kinds of asexual reproduction
Answer
5 kinds of asexual reproduction are:
- Binary fission
- Budding
- Fragmentation
- Spore formation
- Vegetative reproduction
Name the 4 kinds of artificial vegetative propagation
Answer
4 kinds of artificial vegetative propagation are:
- Cutting
- Layering
- Grafting
- Micro-propagation
Name the 3 main pollinating agents
Answer
3 main pollinating agents are:
- Insects
- Wind
- Water
Name the 2 kinds of unisexual flowers
Answer
2 kinds of unisexual flowers are:
- Staminate (male flower)
- Pistillate (female flower)
Name the 4 whorls of a bisexual flower
Answer
4 whorls of a bisexual flower are:
- Calyx
- Corolla
- Androecium
- Gynoecium
Give reasons — Gardeners prefer to grow certain plants vegetatively.
Answer
Gardener prefer to grow certain crops by vegetative method because of the following reasons:
- Reproduction by vegetative parts takes place in a shorter time.
- New plants, thus produced, spread very fast in a small area.
- It is a surer method of propagation.
- All the good characters of the mother plant are retained by the daughter plants.
Give reasons — Artificial pollination is useful to plant breeders.
Answer
Artificial pollination is practiced by plant breeders for developing new varieties. The breeders select two different varieties of a crop plant with desired characteristics. For example, one variety maybe high yielding while the other maybe disease-resistant. Cross breeding between them is done by artificial pollination. Many high-yielding varieties of rice, wheat, maize, etc. have been produced by this process.
Distinguish between the following pairs on the basis of the information in the brackets.
Self pollination and Cross pollination (definition)
Answer
Difference between Self pollination and Cross pollination on the basis of definition:
| Property | Self pollination | Cross pollination |
|---|---|---|
| Definition | The process of transfer of pollen grains from the anthers to the stigma of the same flower, or another flower of the same plant is called self pollination. | The process of transfer of pollen grains from anther of one flower to stigma of other flower of different plants of the same species. |
Distinguish between the following pairs on the basis of the information in the brackets.
Pollen grain and Ovule (location in the flower)
Answer
Difference between Pollen grain and Ovule on the basis of location in the flower:
| Property | Pollen grain | Ovule |
|---|---|---|
| Location in the flower | Located in anther (androecium) | Located in ovary (gynoecium) |
Distinguish between the following pairs on the basis of the information in the brackets.
Sepals and Petals (function)
Answer
Difference between Sepals and Petals on the basis of function:
| Property | Sepals | Petals |
|---|---|---|
| Function | It protects the flower at bud stage. | It attracts insects for pollination. |
Distinguish between the following pairs on the basis of the information in the brackets.
Chlorella and Spirogyra (mode of asexual reproduction)
Answer
Difference between Chlorella and Spirogyra on the basis of mode of asexual reproduction:
| Property | Chlorella | Spirogyra |
|---|---|---|
| Mode of asexual reproduction | Multiple fission | Fragmentation |
Distinguish between the following pairs on the basis of the information in the brackets.
Vallisneria and Trapa (kind of pollinating agent)
Answer
Difference between Vallisneria and Trapa on the basis of kind of pollinating agent:
| Property | Vallisneria | Trapa |
|---|---|---|
| Kind of pollinating agent | Water | Insects |
Draw a neat and labelled diagram of the section of a typical flower. From the parts labelled by you, name the parts matching the description given below :
(a) This part attaches the flower to the shoot.
(b) The flattened part of the pedicel.
(c) The outermost whorl of the flower.
(d) The male reproductive organ of the flower.
(e) The part of carpel which receives pollen grains.
Answer
Below labelled diagram shows the section of a typical flower:
(a) This part attaches the flower to the shoot — Pedicel
(b) The flattened part of the pedicel — Thalamus
(c) The outermost whorl of the flower — Calyx
(d) The male reproductive organ of the flower — Androecium
(e) The part of carpel which receives pollen grains — Stigma