The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
Flowering plants are the most diverse group of plants with 300,000 known species. They are also called angiosperms and produce seed-bearing fruits. Flowers are the reproductive organs of flowering plants and the most important part of plants that distinguishes them from other seed plants. These lead to the speciation of angiosperms, helping them adapt to diverse ecological niches. The flowering plants reproduce by the pollination process. In this, the pollen grains are transferred from the anther of a male flower to the female flower’s stigma, where fertilisation occurs, and the seed is formed.
It is an asexual method of plant reproduction that takes place in leaves, roots, and stems. This can happen through fragmentation and regeneration of plant-specific vegetative plants. Vegetative propagation is unique to plants. The same attribute is also used for commercial value and by ardent gardeners who know their plants well. Seeds are not always essential for the growth of plants. Vegetative propagation, such as grafting and budding, encourages the growth of new plants from the vegetative parts of older plants.
The various types of vegetative propagation are:
Natural Vegetative Propagation Natural vegetative propagation takes place when plants grow and develop naturally without human interference. The development of adventitious roots can facilitate natural vegetative propagation. New plants may emerge from the roots, stems, and leaves of the parent plant. Plant structures growing from the stem are known as runners, tubers, rhizomes, bulbs, etc.
Artificial Propagation Humans perform artificial propagation in fields and laboratories. The most common types of artificially occurring vegetative reproduction include:
Cutting: A part of a plant, typically a stem or a leaf, is cut and planted in the soil. Plant cuttings are sometimes treated with hormones to induce root development. A new plant is formed from the adventitious roots in the cutting process.
Grafting: In grafting, a cutting from another plant is tied to the stem of a plant rooted in the soil. The grafting tissues are integrated with the tissues of the plant rooted earlier, and it develops as a single plant over time.
Layering: The stem of a plant is bent towards the ground and is filled with soil. Adventitious roots then grow from the soil-covered parts of the plant. The attached stem with developing roots is known as a layer.
Tissue Culture: Plant cells from different parts of a plant are cultivated in a laboratory to grow a new plant.
A flower that contains both male and female reproductive organs is called a bisexual flower. The male reproductive organ is called the androecium, and the female reproductive organ is called the gynoecium. The bisexual flower is made up of calyx, corolla, stamens, and carp. The unit of the calyx is called a sepal. The sepals are green, just above the flower stalk. The corolla unit is called a petal.
Petals have different colours and are above the sepals. The androecium is the male reproductive part of the flower and is also called a stem. Stamen is made of an anther and a filament. The gynoecium is the female reproductive part of the flower and is also called carpel. Style, stigma, and ovary are the parts of the carpel.
Pollination is a method by which pollen grains are picked from the anther, which is the male part of the flower, and transferred to the female part of the flower called the stigma. The pollination process begins when the pollen grains of the respective flowers land on the stigma and form a pollen tube using the style length that connects the stigma and the ovaries. After the pollen tube is finished, the pollen grains transmit the sperm cells from the grain to the ovaries.
Later, the fertilisation process takes place when the sperm cells reach the ovaries and the egg cells. The seed is then released from the parent plant, allowing it to grow into a plant and continue the reproductive cycle using the pollination method.
Types of Pollination
All plants with flowers rely entirely on the method of pollination for reproduction. There are two types of pollination, namely self- and cross-pollination.
Self-pollination: It is the primary type as it involves a single flower. Self-pollination occurs when pollen grains fall directly from the anther into the flower stigma.
Cross-pollination: It is a complex form of pollination that allows pollen grains to be transferred from the anther of the flower to the stigma of another flower.
In this chapter, we read about flowering plants. We also learned concepts like bisexual flowers, pollination, and types of pollination.
Define pollination. Pollination is a biological process in which pollen grains are transferred from the anther to the stigma.
How does pollination take place in plants? In pollination, the pollen grains are transferred from the stamen to the stigma of the same plant or the flowers of different plants.
What is cross-pollination? Cross-pollination is a complex pollination type during which the pollen grains are transferred from the anther of one flower to the stigma of another flower.
What are the most important parts of a flower? The important parts of a flower are sepals, petals, stamens, and pistils.
What is the vegetative part of a flower? Sepals and petals are the vegetative parts of a flower.