The ivum is one of the largest female reproductive cells that can grow into a new organism when it is fertilized with sperm. In humans and many other mammalian species, the ovum is larger than the sperm cell.
An ovum is a haploid gamete with 23 chromosomes (X, 22 autosomes). It develops during embryological development in the ovary.
Origin
The origin of ivum was first documented in 1827 by Karl Ernst von Baer in his pamphlet De ovi mammalium et hominis genesi (On the Genesis of the Ovum of Mammals and of Men). The ovum is the female reproductive cell which develops into a new organism when fertilized with a sperm cell.
The ovum has a central nucleus which contains the genetic material of the female. This is surrounded by the cell plasma or yolk which is a source of nutrition for the egg cell.
A haploid egg cell contains only 23 chromosomes, half the normal number of chromosomes found in other body cells. These chromosomes fuse together during fertilization, creating a zygote which quickly develops into an embryo and eventually a newborn baby.
In all mammals except monotremes, a female gamete or ovum is fertilized inside her body with a male gamete or sperm cell. Fertilization takes place through the action of hundreds of millions of sperm cells which compete with each other for one egg cell.
Structure
An ivum is a spherical cell which is produced from one of the female reproductive organs, the ovary. The ovum has the ability to grow into a new organism after being fertilized with a sperm cell.
The ovum has a central nucleus and cytoplasm which contain half of the chromosomes. The cytoplasm contains nutrients that are essential for the egg cell to develop.
There is a large nucleus called the germinal vesicle which is covered by a thin nuclear membrane called the vitelline membrane. It also contains a nucleolus or germinal spot.
The ovum is enclosed by another primary membrane called the zona pellucida which has a narrow space between it and the vitelline membrane. Under the zona pellucida are several layers of epithelial cells which radially form corona radiata. These cells release chemical signals that attract sperm to the ovum. These cells also protect the ovum from physical injury and help provide nutrients to the developing embryo.
Function
Ovum (plural for egg) is one of the most important cells in a female reproductive system. It is a very complex cellular structure comprising of three main parts, namely a central nucleus, cytoplasm and a cellular membrane. The ovum’s nucleus is responsible for the female’s genetic material while the cytoplasm holds the essential nutrient and energy requirements.
The function of the ovum is to produce the egg which is then transported via the fallopian tube to the uterus. Once the egg reaches the uterus, it makes good on its promise of fertilisation by joining with a sperm cell that is likely to have already made its way there from the female’s ovaries. The ovum is a major contributor to the growth of the embryo by providing it with an impressive array of nutrients and nourishments until the placenta starts doing its part. It is no small task as the ovum is a fairly large cell measuring about 120 um in diameter and has a few snaggletooths along the way.
Fertilization
Once a month, a woman releases an egg (ovum) into her fallopian tubes. After sexual intercourse, sperm move from the vagina through the cervix and uterus to meet the egg in the fallopian tube.
When sperm and an egg come together, they form what is called a zygote. This is a single ball of cells that divides repeatedly as it moves down the fallopian tube to your uterus, where it implants in the wall of your uterus and continues to develop into an embryo.
A zygote contains 46 chromosomes, each carrying around 2,000 genes. The chromosomes help the zygote develop into an embryo that continues to grow, forming a baby.
