Gynoecium – Definition, Concept, Parts, Functions
The female reproductive part of the flower is known as Gynoecium. It is the part that produces ovaries which are later on finally converted into fruit after sexual reproduction. The gynoecium is the inward whorl of the flower. The gynoecium is also referred to as female because they produce the female gametophyte.
Reproduction is a biological process in which living organisms produce offspring similar to them. Reproduction is necessary to ensure the continuity of species on earth. In sexual reproduction, there is a chance of evolution which is necessary to adapt and survive the changing environment and climate. The flower is the reproductive unit in most sexually reproducing plants. A flower consists of 4 whorls. These whorls are arranged circularly one after the other on the thalamus.
Structure of Flower
- Calyx: is the outermost whorl that offers flower which consists of sepals and usually is green.
- Corolla: Corolla is the collection of petals of a flower. It is usually colorful or brightly colored to attract pollinators for pollination.
- Androecium: An androecium is the male reproductive part of the flower.
- Gynoecium: The gynoecium is the female reproductive part of the flower.
It’s the female reproductive structure of a flower. The gynoecium consists of one or more carpels. It is present at the center of the flower. The gynoecium consists of three main parts. Those are stigma, style, and ovary.
Structure of Gynoecium
The topmost part of the female reproductive system is called stigma. The main purpose of stigma is to catch hold of pollen grains exposed to the air or surroundings. The surface of the stigma will be sticky by having hair-like structures or rough surfaces. Stigma provides a landing platform for pollen grains, playing a very crucial role in pollination. Stigma consists of highly nutrients enriched tissue that helps for the development of pollen tubes toward the ovule.
Functions of Stigma
During the process of fertilization, the following grains land on a stigma-a sticky receptive surface. Stigma recognizes the right pollen grains, meaning belonging to the same species. Stigma acts as a surface or provides an area for the germination of pollen. Even if the pollen grains of other species land on the stigma, it won’t allow germination of those pollen grains. Initiation of fertilization occurs through the growth of pollen tubes through the pollen grain. The entry of Poland tubes of other species is strictly not allowed. The plant produces I kind of chemical which dissolves pollen of other species, not allowing them to germinate.
The long stock-like filamentous structure which connects the ovary to the stigma is called style. The pollen tube grows in the style to ensure a safe journey of pollen grains. After pollination, the pollen tube starts growing towards the ovule through style. Once the pollen tube is grown, the pollen grains are passed to the ovary. It leads pollen (male egg cells) to the ovules (female egg cells).
The style is the location where the compatibility of a pollen grain is tested. The style performs an essential function during fertilization. It not only allows the growth of pollen tubes but also stops the growth of pollen tubes of incompatible pollen grains.
Functions of Style
Once the pollen grain lands on the stigma as a process of germination, it starts growing a pollen tube which flows through the style. The vegetative cell provides the required nutrition for the growth of the pollen tube. Thus, style acts as a path for male gametes to reach the ovary and then to the ovule.
It is the most important part of the gynoecium where the ovules are produced. Usually, it consists of bulged or enlarged structure. If a gynoecium is not having an ovary, then the flower is considered to be sterile or parthenogenesis gynoecium.
The ovule is the female gametes. Ovules are also called megasporangia. The ovule protects the female gametes and also provides nourishment to the developing embryo through the placental wall. The ovals are located at the innermost part of the ovary and will be growing into seeds upon fertilization. The ovule is attached to the placenta by a structure called a funicle. The funicle is responsible for providing new trends for the developing embryo.
Functions of the Ovary
The ovary contains ovules, which are the female egg cells necessary for the process of fertilization. Pollen merges with the ovule and fertilizes it. Ovules are the available seeds. After fertilization, these ovules develop into seeds. The ovary matures into a fruit.
Classification of Flower on Basis of Gynoecium
Flowers can be differentiated on the different basis:
Depending on the arrangement of carpels, the flower is classified into three types of flowers
- Monocarpous: If a flower consists of a single carpel, it is called Monocarpous or unicarpellate gynoecium. Examples: Avocado, peach, etc.
- Apocarpous: A flower consisting of two or more free carpels that are not joined together is called an apocarpous or apocarpous flower. Examples: Strawberry, buttercup, Michelia, Lotus, and Rose.
- Syncarpous: A flower consisting of two or more carpels that are fused, and joined together is called a syncarpous or syncarpous flower. Examples: Tulip, China rose, Mustard, tomato, etc.
Depending on the type of ovary present in a flower, it is classified into three types of flowers
- Hypogynous flower: if a flower is having ovary above the other parts of the flower (meaning superior ovary) then the flower is considered a hypogynous flower. Example: Mustard.
- Epigynous flower: if the ovary is placed below the parts of the flower (meaning inferior ovary) then the flower is considered an epigynous flower. Example: Coriandrum.
- Perigynous flower: is there over is placed at the same height as with other floral parts then the flower is called a perigynous flower. Example: Pea.
Depending on the number of chambers present in the ovary, it is classified into the following types
- Unilocular ovary: ovary consisting of only one chamber is called a unilocular ovary. Example: Pea.
- Bilocular ovary: if the ovary is having two chambers, then the ovary is called a Bilocular ovary. Example: Petunia.
- Trilocular ovary: if the ovary is having three chambers, then the ovary is called a trilocular ovary. Example: Asphodelus.
- Multilocular ovary: if the ovary has more than three chambers, it can be called a multilocular ovary. Example: Shoe-flower.
The basal part of the calyx, corolla, and stamens form the cup-like structure in angiosperms which is known as Hypanthium. Also known as the floral cup of the floral tube. It is present in the flowers of many families and helps in the identification via its shape.
FAQs on Gynoecium
Question 1: Which is the female reproductive unit in the angiosperms?
The reproductive unit in the angiosperms is a flower. A flower is meant for sexual reproduction.
Question 2: Mention four different kinds of whorls of a flower.
These are the four different kinds of whorls of a typical flower.
Question 3: What is Gynoecium?
The gynoecium is a female reproductive part of the flower. The gynoecium is made up of one or more carpels.
Question 4: What is the meaning of androecium?
The male reproductive part of the flower is known as the androecium. Consisting of filament and anther having stamens.
Question 5: Mention parts of a carpel and define them.
A carpel has three parts namely:
- Stigma The stigma is the receptive surface for pollen grains. It usually lies at the tip of the style
- Style Style is an elongated tube that connects the ovary to the stigma.
- Ovary Ovary is the enlarged basal part of a carpel.
Question 6: What is an apocarpous flower? Give an example.
In a flower, a condition where more than one carpel is present and if these carpels are free, separate, or not joined together is known as an apocarpous condition or apocarpous gynoecium. The flower having such apocarpous gynoecium is called the apocarpous flower.
Example: Lotus and Rose.
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