Reproduction in Plants

Pollen is produced in the :

1. Filament
2. Style
3. Pistil
4. Anther

Answer

Anther

Reason — The anther consists of four sac-like structures that produce pollen for pollination.

Reproductive whorls of a flower are:

1. Stamens and carpels
2. Sepals and petals
3. Sepals and stamens
4. 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 :

1. Artificial vegetative propagation
2. Sexual reproduction
3. Artificial pollination
4. 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.

Sanjay, a research scholar wants to develop a disired variety of Guava in his orchard. Which of the following methods of vegetative propagation will be the most suitable for him?

1. Cutting
2. Grafting
3. Layering
4. Micropropagation

Answer

Grafting

Reason — Grafting is the most suitable method for developing a desired variety of Guava as it combines the qualities of two different plants of related species, ensuring better yield and uniform fruit quality.

Flowers borne on the shoot system of a plant serve as reproductive part. Which of the following reasons supports this statement ?

P. Flowers bear stamens and carpels.
Q. Flowers make the plant attractive.
R. Flowers produce fruits with seeds.

1. Only P
2. Only Q
3. Only P and R
4. Only Q and R

Answer

Only P and R

Reason — Flowers contain stamens (male reproductive organs) and carpels (female reproductive organs) which are essential for fertilization. Flowers develop into fruits after fertilization, and these fruits contain seeds, which are the next generation of plants.

Flowers indeed make the plant look attractive, but this does not serve the purpose of being the reproductive part of a plant.

Mamta is curious to study different kinds of pollination among flowers present in her garden. She has performed artificial pollination in the following ways :

P. Pollination within a flower.
Q. Pollination between flowers of same plant.
R. Pollination between two flowers of two different plants of same species.
S. Pollination between two flowers of two different plants of the different species.

Which of the ways given abo explains 'cross-pollination'?

1. Only R
2. Only P, Q and S
3. Only P, R and S
4. Only P and S

Answer

Only R

Reason — Cross-Pollination occurs between two flowers on different plants of the same species.

Cross-pollination is considered better than self-pollination because it produces healthier and more viable seeds. But it cannot occur by itself. Cross-pollination occurs with the help of certain agents like wind, water, insects, etc. Which of the following features of flowers are not suitable for insect-pollination ?

P. Flowers are usually small and of dull colours.
Q. Flowers are not scented and do not produce nectar.
R. Flowers produce sticky pollen grains.

1. Only Q
2. Only Q and R
3. Only P and R
4. Only P and Q

Answer

Only P and Q

Reason — Large flowers of brightly coloured petals, that are scented, produce nectar as food for insects, and produce sticky pollen grains are suitable for pollination by insects.

Assertion (A): The edible portion of potato plant is the root as it grows and develops under the soil.

Reason (R): The root is swollen due to the storage of food material which is rich in starch.

1. Both A and R are true.
2. Both A and R are false.
3. A is true and R is false.
4. A is false and R is true.

Answer

Both A and R are false.

Explanation — The edible part of the potato is a modified stem called a tuber, not a root, even though it grows underground. The swelling occurs due to food storage, but it's the stem, not the root, that stores starch.

Assertion (A): Carrot is a biennial plant which stores food material in its roots in the first year.

Reason (R): This food is utilized in the second year to produce flowers and viable seeds, i.e. to reproduce sexually.

1. Both A and R are true.
2. Both A and R are false.
3. A is true and R is false.
4. A is false and R is true.

Answer

Both A and R are true.

Explanation — Carrot is a biennial plant, meaning it completes its life cycle in two years. In the first year, it stores food in its roots, which is then used in the second year for flowering and seed production, enabling sexual reproduction.

Assertion (A): Calyx is the outermost whorl of a flower which consists of large, fragrant and brightly coloured petals.

Reason (R): As petals are brightly coloured and fragrant, they can be noticed by insects easily and help in cross pollination.

1. Both A and R are true.
2. Both A and R are false.
3. A is true and R is false.
4. A is false and R is true.

Answer

A is false and R is true.

Explanation — Calyx, the outermost whorl of a flower consists of tiny leaf-like green structures called sepals, for providing the inner parts of flower with necessary protection.

Corolla, the second inner whorl of the flower is made up of petals that are large, fragrant and brightly coloured. They can be noticed by insects easily and help in cross pollination.

Assertion (A): Micropropagation is the propagation or multiplication of plants by a special technique called 'tissue culture'.

Reason (R): It is called 'micropropagation' because this technique is applicable to micro-organisms only.

1. Both A and R are true.
2. Both A and R are false.
3. A is true and R is false.
4. A is false and R is true.

Answer

A is true and R is false.

Explanation — Micropropagation involves growing plant cells, tissues, or organs in a laboratory setting to produce plantlets. These plantlets are then transferred to the soil.

Assertion (A): Vallisneria is a good example of wind-pollinated flower, even though the plant is aquatic.

Reason (R): Both male and female flowers of Vallisneria float on the surface of water and get pollinated with the help of wind.

1. Both A and R are true.
2. Both A and R are false.
3. A is true and R is false.
4. A is false and R is true.

Answer

Both A and R are false.

Explanation — Vallisneria, an aquatic plant, is a good example of water-pollinated flower. Both male and female flowers of Vallisneria float on the surface of water and get pollinated with the help of water.

Fill in the blanks by selecting suitable words:

(unisexual, fertilisation, fruit, stamen, anther, bisexual, pollination, seed, ovary)

1. A flower that bears both the male and the female parts is known as ............... flower.

2. A flower bearing only male or female parts is known as ............... flower.

3. Transfer of pollen grains from the anther to the stigma is known as ...............

4. Fusion of male cell with female cell is called ...............

5. The ovule develops into a ...............

6. The ovary of the flower develops into a ...............

Answer

1. A flower that bears both the male and the female parts is known as bisexual flower.

2. A flower bearing only male or female parts is known as unisexual flower.

3. Transfer of pollen grains from the anther to the stigma is known as pollination.

4. Fusion of male cell with female cell is called fertilization.

5. The ovule develops into a seed.

6. 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 —

1. Self-pollination
2. Cross-pollination

Give two features of flowers which favour pollination by insects.

Answer

Two features of flowers which favour pollination by insects are —

1. These flowers are large with coloured petals, to attract insects.
2. 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 —

1. They are usually small and are of dull colours.
2. 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:

1. Binary fission
2. Budding
3. Fragmentation
4. Spore formation
5. Vegetative reproduction

Name the 4 kinds of artificial vegetative propagation

Answer

4 kinds of artificial vegetative propagation are:

1. Cutting
2. Layering
3. Grafting
4. Micro-propagation

Name the 3 main pollinating agents

Answer

3 main pollinating agents are:

1. Insects
2. Wind
3. Water

Name the 2 kinds of unisexual flowers

Answer

2 kinds of unisexual flowers are:

1. Staminate (male flower)
2. Pistillate (female flower)

Name the 4 whorls of a bisexual flower

Answer

4 whorls of a bisexual flower are:

1. Calyx
2. Corolla
3. Androecium
4. 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:

1. Reproduction by vegetative parts takes place in a shorter time.
2. New plants, thus produced, spread very fast in a small area.
3. It is a surer method of propagation.
4. 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:

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:

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:

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:

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:

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