Content Writer
Ovule is a part of the female reproductive system that forms the seeds of flowering plants.
- It is situated in the ovaries near the base of the carpel base.
- It has an opening at the top part called Stigma and a neck part which is called Style.
- Ovules develop into seeds after fertilization in plants.
- Ovule starts to swell after fertilization and starts to toughen up.
- The ovary starts to grow around it and becomes a fruit.
The number of ovules differs from one plant to the other. For example, plants like Kiwi have more than one ovule, whereas Avocado has only one ovule.
Read More: NCERT Solutions For Class 12 Biology Sexual Reproduction in Flowering Plants
Key Terms: Ovule, Flowering Plant, Ovary, Seeds, Fruit, Fertilization, Reproductive Organ, Flower, Nucellus
What is Ovule?
[Click Here for Sample Questions]
Ovule is the organ that forms the seeds of flowering plants. It is formed in the ovary of the flower and consists of nucellus protected by integuments, precursors of embryo or endosperm, and the seed coat, respectively.
- Ovule plays an important role in reproduction in plants.
- It is situated near the carpel base.
- Ovule is a curvy horseshoe-shaped part present in the ovary.
- The primary function of the ovules is the development of the seeds.
- It is also known as megasporangium.
- A mature ovule includes food tissue that is covered by one or two seed coats, which is also known as the Integuments.
![Structure of ovule]()
Structure of Ovule
Read More:
Components of Ovule
[Click Here for Previous Year Questions]
Ovule in any flowering plant has mainly three parts which are as follows:
- Nucellus
- Integuments
- Female Gametophyte
Nucellus
- Nucellus is the largest and the most important part of the ovule.
- It holds the embryo sac along with nutritive tissues.
- These nutritive tissues provide the required nutrients to the embryo.
- Nucellus can be found in the innermost part of the Ovule.
- This part also protects the embryo from rough weather conditions.
Read More: MCQs on Reproduction in Flowering Plants
Integuments
- Integuments are the outer layer that covers the ovule part of the flowering plant.
- This part later transforms into the seed coat after fertilization.
- The number of integuments differs from gymnosperms and angiosperms.
- The nucleus and integuments remain connected, and it is located near the micropyle.
- The tissues that make this part are also known as the chalazal tissues.
Female Gametophyte
- The reproductive part that produces gametes is situated in the female gametophyte.
- The female gametophyte has a single unpaired chromosome, therefore it is haploid.
- It is primarily called the embryo sac or mega-gametophyte.
Location of Ovule
[Click Here for Sample Questions]
Ovule is located inside the gynoecium, a part of the flower present in angiosperms. The fruit wall is developed from the ovary of the gynoecium. The ovule is connected to the placenta through a funiculus structure. Different plants have different ovule attachments such as
- Apical Placentation
- Parietal Placentation
- Superficial Placentation
- Basal Placentation
- Axile Placentation
- Free-Central Placentation
- Marginal Placentation
Types of Ovule
[Click Here for Previous Year Questions]
Ovule can be categorized into six types depending upon their shapes and structures:
- Orthotropous or Atropous: The body of this ovule is mostly straight and the chalaza along with the funicle and micropyle remain aligned.
- Anatropous: This ovule curls up so much that it remains inverted through the development of the embryo. Hence, the micropyle is located near the hilum. In this type of ovule, a hilum scar can be seen where the funicle and the seed are connected to the fruit wall.
- Hemi-Anatropous: This ovule remains lying on its side due to the development towards the right angles of the funicle.
- Campylotropous: The connection between the chalaza and the micropyle gets broken. The ovule body is slightly curved in this case.
- Amphitropous: This ovule is excessively curved and looks like a horse-shoe kind of shape.
- Circinotropous: It is the most unique type of ovule. The funicle part is extremely long such that it almost makes a circular shape around the ovule. In this type of ovule, the micropyle is pointed upwards.
![Types of Ovule]()
Types of Ovules
Check More:
Functions of Ovule
[Click Here for Sample Questions]
The important functions of Ovule are as follows:
- Ovule plays an integral role in the plant reproductive system.
- It makes reproduction in plants less complicated.
- It protects the embryo throughout the fertilization process from rough weather.
- Ovule includes nutritive tissues that provide the required nutrients to the embryo.
Read More: Morphology of Flowering Plants
Things to Remember
- Ovule is an organ in the female reproductive part of a seed plant.
- It is situated in the ovaries near the carpel base.
- It has an opening at the top part called Stigma, and a neck part called Style.
- Ovule includes three parts namely Nucellus, Integuments, and Female Gametophyte.
- There are six types of Ovules based on their shape namely Orthotropous, Anatropous, Hemi-Anatropous, Campylotropous, Amphitropous, and Circinotropous.
- Ovule includes nutritive tissues that provide the required nutrition to the embryo.
Previous Years Questions
- Ovule integument gets transformed into… [WBJEE 2011]
- The megasporangium proper of an angiosperm ovule is… [MHT CET 2017]
Sample Questions
Ques. Define Ovule. (2 Marks)
Ans. Ovule is a part of a flowering plant that nurtures and develops into seeds on fertilization. It is located in the ovaries near the carpel base. It has an opening at the top part named stigma and has a neck called a style. It is made up of three major components namely Nucellus, Integuments, and Female Gametophyte.
Ques. Is Ovule the fruit or seed? (1 Mark)
Ans. Ovule is a component of the plant reproductive system that constitutes the female reproductive system. On fertilization, the ovules mature into the seed and the ovary develops into a fruit.
Ques. Explain the structure of the ovule. (3 Marks)
Ans. Ovule is made up of three parts called Nucellus, Integuments, and Female Gametophyte.
- Nucellus: It is the largest and the most important part of the ovule that holds the embryo sac along with nutritive tissues. It is found in the innermost part of the Ovule and offers the required nutrition to the embryo. It also protects the embryo from rough weather conditions.
- Integuments: It is the outer layer that covers the ovule and transforms into the seed coat after fertilization. The number of integuments varies in gymnosperms and angiosperms.
- Female Gametophyte: It produces gametes and includes a single unpaired chromosome.
Ques. What are the functions of the Ovule? (3 Marks)
Ans. The functions of the ovule are as follows:
- It protects the embryo from rough weather and external conditions.
- It helps in the further reproduction of plants.
- It includes nutritive tissues required to nourish the embryo.
Ques. What are the types of Ovules? (3 Marks)
Ans. On the basis of their shapes and structures, Ovules can be classified into six major types:
- Orthotropous or Atropous
- Anatropous
- Hemi-Anatropous
- Campylotropous
- Amphitropous
- Circinotropous
Ques. Which is the most unique kind of Ovule? (2 Marks)
Ans. Circinotropous is the most unique type of ovule. In this type of ovule, the funicle part is extremely long. It is so much longer that it almost makes the shape of a circle around the ovule. In the case of Circinotropous, the micropyle is pointed upwards.
Ques. Is Ovule the same as Ovary? (5 Marks)
Ans. No, Ovary and Ovule are two different components is a flowering plant. The differences between ovule and ovary are as follows:
| Ovule | Ovary |
| It is a part of the ovary of plants that contains the female germ cell. | It is the female reproductive organ in which eggs are produced. |
| It occurs only in plants. | It occurs in both animals and plants. |
| One to more ovules occurs inside the ovary of plants based on the species. | A pair of ovaries occurs in animals and a single ovary is present in each plant. |
| It develops into a female gamete in plants. | It produces and matures the female gametes. |
| It turns into seeds after fertilization. | It turns into fruit after fertilization. |
Ques. Explain the process after pollination of ovules. (2 Marks)
Ans. After pollination, when pollen reaches the stigma of a particular flower, a series of processes take place that results in fruit production. It is only after fertilization, that the ovule matures into a seed, and also serves as a food source for the plants. After the ovule seals an embryo inside the seed coat, the ovary finally transforms into a fruit.
Ques. List the various parts of a flower. (2 Marks)
Ans. The parts of a flower are as follows:
- Pedicle
- Calyx
- Petals
- Sepals
- Stamen
- Pistil
- Receptacle
Ques. What is Pollination? (2 Marks)
Ans. Pollination is defined as the transfer of pollen grains from the anther of a flower to the stigma of a similar or a separate flower. It is an integral process in the reproduction of plants as it brings the male gamete nearer to the female egg and lets them fuse and generate new offspring.
Check-Out:
Comments