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The ovule is the female organ of the egg. It is where a woman’s genitals are that are fertile and motherly. The eggs are deposited in the ovaries below the mat, which includes an opening at the top, a resistance, and a tick called a process. When united, these cells will eventually become a seed, which will mature into a mature plant. Ovule is also known as megasporangium in flowering plants.
After fertilization, the egg develops, and its wall begins to form a seed. In contrast, the ovary begins to grow around it and is destroyed in the fruit. Remember that some plants, like avocados, have only one egg in their egg, while other plants, like kiwi, have many eggs, which will eventually become many seeds in the fruit.
Location of the ovule:
The ovule is found inside the gynoecium, the part of the flower present in angiosperms or flowering plants. The fruit wall will eventually break from the gynoecium’s ovary, which produces more than one egg. The funiculus is a stem-like structure that connects the eggs to the placenta. As plants show different patterns of ovulation or placenta, including:
• Apical placentation.
• Basal placentation.
• Axial placentation.
• Marginal placentation.
• Free central placentation.
• Parietal placentation.
• Advanced Placement.
Eggs are produced in gymnosperms such as conifers, usually within the ovule cone, above the ovule-producing scale (ovuliferous). Eggs are produced on the surface of the leaf in the seeds of old ferns.
Components of ovule:
The ovule is formed by the nucellus, the integuments from the outside, and the female gametophyte (called the embryo sac in the flowers), which is right in the middle.
The nucellus is the largest part of the egg. It stores the “embryonic sac” as well as nutritious tissue and remains present in other flowers after fertilization as a source of food for the “embryo”.
The integument is the hard outer protective layer of the ovum. In the pictures below, we can see that gymnosperm, such as pine and spruce trees, often have a tegument in the ovule, which is why they are called unitegmic. On the other hand, angiosperms, such as maples and daisies, usually have two integuments, and the ducts are bitten. The integument covers the nucellus except for a thin layer called the micropyle.
Types of ovules:
There are six types of eggs per plant. These types of eggs are based on their shape.
Orthotropous or Atropous:
The area where the nucellus and integuments meet is known as a chalaza. Orthotropous, the body of the plant ovule, is straight so that the chalaza, funiculus (which attaches the plant ovule to the placenta), and micropyle overlap.
The scar indicates the place where the seed is attached to the fruit by a funicle called the hilum. In Anatropus, the ovules are placed entirely in the crescent so that the micropile is close to the hilum.
Here, the eggs take the shape of a right angle above the funicle. Its final shape is like an egg lying on its side.
The shape of the Campylotropous ovum is folded, and the arrangement occurs between the chalaza and the micropyle ends; therefore, the “embryonic sac” becomes slightly curved.
The body of the amphitropous ovum is curved so that the egg and embryo sac is shaped like a horse.
The shape of circinotropous is the most distinctive of all. The funiculus in the case of a circinotropous ovule is so long that it forms a complete circle around the ovule and its micropile points upwards. It is considered the most complex of the six types of ova.
Functions of the ovules:
The seed of a plant plays an important role in the reproduction of the plant. The reproductive process becomes easier with the presence of the ovum. When a pollen grain lands on a single flower, the plant produces a pollen tube as it develops. Then this pollen tube reaches the anther of the plant, and after that reproduction can take place, as the nucleus of the pollen grain is sent down to connect with the nucleus in the embryo sac.
Pollination of ovules:
A series of events that occur after mating lead to fruit formation. When the pollen reaches the stigma of another flower, certain events occur that result in the formation of seeds. The flower must be of the same type. The eggs hatch into seeds after mating and these seeds become food for plants again. Finally, the ovary turns into a fruit after sending an egg that closes the “embryo” inside the line.
Fun points about Ovule:
The ovule itself is a reproductive organ that develops into a seed.
In angiosperms, the seed develops inside the ovary, while in gymnosperms, the seed develops inside the female cone. In the store, the eggs are protected by megasporophyll, but in some versions, they are stored without sharing.
The developing ovule of an angiosperm consists of membranes, integuments, and an embryo sac.
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