Reproduction in Plants

Anther

Reason — The anther consists of four sac-like structures that produce pollen for pollination.
Filament supports the anther. Style is part of the female structure (connects stigma to ovary). Pistil is female reproductive part (does not produce pollen).

Stamens and Carpels

Reason — Stamens are the male reproductive parts of the flower.
Carpels are the female reproductive parts of the flower.
Sepals and petals are non-reproductive (accessory) whorls.

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.
It is not sexual reproduction (no gametes involved). It is not pollination (no transfer of pollen).

Grafting

Reason — Grafting is the most suitable method for developing a desired variety of guava as it can combine desirable qualities of two plants of the same or related species.
Cutting is not very reliable for guava. Layering is possible but less efficient for large-scale improvement. Micropropagation is advanced and costly, mainly used in labs.

Only P and R

Reason — Flowers contain stamens (male reproductive organs) and carpels (female reproductive organs) which are essential for fertilisation. Flowers develop into fruits after fertilisation, 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.

Only R

Reason — Cross-pollination occurs between two flowers on different plants of the same species.
Pollination within a flower is called self-pollination. Pollination between flowers of the same plant is also called self-pollination. Pollination between flowers of different species is not cross-pollination within the same species and normally does not result in fertilisation.

Only P and Q

Reason — Insect-pollinated flowers are usually large, brightly coloured, scented and nectar-producing. They also produce sticky pollen grains so that the pollen can stick to the body of insects.
Small and dull-coloured flowers are not suitable because insects are not attracted to them. Flowers with no scent and no nectar are also not suitable because they do not attract insects.

Both A and R are true and R is the correct explanation of A.

Explanation — A is true as carrot is a biennial plant, meaning it completes its life cycle in two years.
R is true as 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.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

A is false and R is true.

Explanation — A is false as 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.

R is true as 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.

Therefore, A is false and R is true is the correct option.

A is true and R is false.

Explanation — A is true as micropropagation involves growing plant cells, tissues, or organs in a laboratory setting to produce plantlets. These plantlets are then transferred to the soil.
R is false because micropropagation is not applicable to micro-organisms only. It is called micropropagation because plants are multiplied from very small plant parts or tissues under tissue culture conditions.

Therefore, A is true and R is false is the correct option.

Both A and R are true and R is the correct explanation of A.

Explanation — A is true as Vallisneria shows a special adaptation for hydrophilous (water-mediated) pollination.
R is true as its male flowers get detached from the plant and float freely until they reach and make physical contact with the female flowers at the water surface.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

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 fertilisation.

5. The ovule develops into a seed.

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

(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

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.

Pollination is the process in which the pollen grains from the anthers are transferred to the stigma of a flower of the same species.

Grafting is an artificial vegetative propagation method in which a shoot or bud called the scion is fixed on another plant called the stock so that both grow together.

Micropropagation is the process of rapid propagation of plants by tissue culture techniques.

The process of fusion of male and female gametes to form a zygote is called fertilisation.

Two ways in which pollination may occur in plants are —

1. Self-pollination
2. Cross-pollination

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.

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.

5 kinds of asexual reproduction are:

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

4 kinds of artificial vegetative propagation are:

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

3 main pollinating agents are:

1. Insects
2. Wind
3. Water

2 kinds of unisexual flowers are:

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

4 whorls of a bisexual flower are:

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

Gardeners prefer to grow certain crops by the 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.

Artificial pollination is practised by plant breeders for developing new varieties. The breeders select two different varieties of a crop plant with desired characteristics. For example, one variety may be high-yielding while the other may be 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.

Difference between Self pollination and Cross pollination on the basis of definition:

Difference between Pollen grain and Ovule on the basis of location in the flower:

Difference between Sepals and Petals on the basis of function:

Difference between Chlorella and Spirogyra on the basis of mode of asexual reproduction:

Difference between Vallisneria and Trapa on the basis of kind of pollinating agent:

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

(a) Potatoes are modified stems, not roots or fruits because they have “eyes” (buds) on their surface, and buds are a characteristic feature of stems. These buds can sprout into new shoots, which shows that potato is an underground stem (specifically, a tuber).

(b) Not every piece of the cut potato will grow into a new plant. Each piece must contain at least one “eye” (bud). The bud has meristematic tissue that can develop into a new shoot and eventually form a complete plant. Pieces without eyes cannot grow.

(c) Ginger, sugarcane and strawberry undergo vegetative propagation. Ginger reproduces by its rhizome, sugarcane by stem cuttings, and strawberry by runners.

Mango, however, is usually propagated through seeds. Therefore, it does not naturally undergo vegetative propagation like the other plants given in the options.