Human Reproductive System
The two important Cells of the Human Reproductive system are Sperm and Ovum, the former being male Reproductive Cell and the latter being a female Reproductive Cell. Both of these Cells are responsible to undergo Fertilisation through fusion and formation of zygote. However, you will learn about the difference between Ovum and Sperm related to certain characteristics, structure and functionalities in this article.
What is Sperm?
It is the male gamete or reproductive cell that plays a major role in the reproduction process in humans and other animals. A motile sperm with a tail also called flagellum is produced by animals and it is known with the name spermatozoa whereas algae and fungi are known to produce non-motile sperm cells called spermatia. Talking about the plants, the flowering group contains non-motile sperm inside the pollen and some plants such as fern and gymnosperms consist of motile sperm.
Human sperm cell is haploid and consists of 23 chromosomes which join with the 23 chromosomes of the female egg or ovum to form a diploid cell. Sperm is stored in the epididymis and during ejaculation, it is released from the penis along with a fluid called semen.
Sperm Structure
Talking about the anatomy of a sperm cell, it can be divided into head and tail. The head contains a nucleus with densely coiled chromatin fibres and is anteriorly surrounded by a thin and flattened sac known as acrosome. Acrosome contains enzymes that help in the penetration into the female egg or ovum. The head portion of a sperm also contains vacuoles. On the other hand, the tail which is also known as flagellum is the longest part of a sperm and goes into a wave-like motion that helps the sperm to swim and penetrate the egg. The four parts of the tail include the connecting piece, principal piece, midpiece and the end piece.
What is Ovum?
Also called the egg cell or ova in plural, it is the female gamete or reproductive cell present in humans and most of the animals. Ovum is non-motile and when the egg or ovum fuse with sperm during fertilisation, a zygote or a diploid cell is formed that can grow further into a new organism. Sometimes, the young ovum of an animal is termed an ovule. Mammals have numerous ova at birth and these mature through oogenesis. In all mammals including humans, the ovum is fertilised inside the female body. It is one of the largest cells in the human body and is visible even to the naked eye without the help of a microscope. It measures approximately 0.1 mm in diameter in humans. Ovum is called the oosphere in algae.
Ovum Structure
Ovum has a cell substance at its centre called the yolk or ooplasm. Ooplasm contains a nucleus named the germinal vesicle and also a nucleolus called the germinal spot. Ooplasm has formative yolk and nutritive yolk, the formative yolk is the cytoplasm of an ordinary animal cell and the nutritive yolk (deutoplasm) is made of rounded granules composed of fatty and albuminoidal substances in the cytoplasm. The latter helps in nourishing the embryo in the early stages of developmental phase in mammals. On the other hand, birds contain egg nutritive yolk which is enough to supply its chick enough nutrients throughout the period of incubation.
We will highlight the differences between sperm and ovum in a tabular chart as follows.
Difference Between Ovum and Sperm
Sperm vs Ovum
Human reproduction is a form of sexual reproduction which helps achieve Human Fertilization. Fertilisation is a process of Fusion of Male and Female gametes to give rise to a new individual Human being. Each gamete or Reproductive Cell carries half of the gene of an organism and when both of the gametes fuse the gene adds up to become complete. In Human beings, we have 46 Chromosomes and so to add up the number of Chromosomes after Fertilisation to be 46 each gamete should have 23 Chromosomes.
In Sexual Reproduction there exists two types of gamete one male and one female. The male gamete is known as Sperm and the female gamete is known as Ovum. These gametes are created by the meiosis division of Human Cells so in that process it will always have half the number of genes that a parent Cell contains, for which they are called haploid. Let us take a look into both types of gamete and see what are the properties they have.
Sperm
Sperm are the male Reproductive Cells that help male organisms to pass down their genes to their offspring. Sperms are formed during the process of Spermatogenesis in the seminiferous tubules of the testes. The process starts with the creation of several successive Sperm Cell precursors which then are transferred into Spermatogonia and get differentiated into Spermatocytes. These Spermatocytes then undergo meiosis, which reduces the number of Chromosomes by half and produces Spermatids.
These Spermatids then transform into mature motile Sperm Cells. This transformation includes the change in shape and size of the Cell. The biggest characteristic of Sperm is the ability to reach/travel to the Ovum. In animals, this is possible by the development of a tail-like structure called a filament. Sperms are the smallest of the Cells in the Human body.
Ovum
Ovum is the female Reproductive Cells that get fertilised by Sperm and create a zygote. Ovum is formed and released by the ovaries. The shape of the Ovum is spherical and non-motile. It usually is the largest Cell in the Human body. The majority of the Ovum is constituted by the cytoplasm. The formation of an Ovum in Human females is completed before birth and the ova are released on a cycled basis throughout their whole reproduction cycle. One Ovum is released by both ovaries on an alternate basis in the mid-day of the menstrual cycle. After that, the Ovum waits in the fallopian tube for the Sperm to reach there and get fertilised.
FAQs on Difference Between Sperm and Ovum
1. What is the main difference between a sperm and an ovum?
The main difference lies in their roles and structure. A sperm is the male reproductive cell (gamete), which is small and motile, designed to travel to the egg. An ovum, or egg cell, is the female gamete. It is much larger, non-motile, and contains the necessary nutrients to support the initial development of an embryo after fertilisation.
2. In terms of size and structure, how do a sperm and an ovum compare?
The ovum is significantly larger than the sperm; it's one of the largest cells in the human body. Here’s a quick comparison:
- Ovum: It is spherical and contains a large amount of cytoplasm, which provides nourishment for the early embryo. It cannot move on its own.
- Sperm: It is a microscopic cell with a distinct head, midpiece, and tail. The tail, or flagellum, allows it to swim towards the ovum. It contains very little cytoplasm.
3. What are the genetic differences between a sperm and an ovum?
Both are haploid cells, meaning they contain half the number of chromosomes of a normal body cell. The key genetic difference is in the sex chromosomes they carry. An ovum always contains one X chromosome. A sperm, however, can carry either an X or a Y chromosome. Therefore, the sperm is the cell that determines the genetic sex of the offspring.
4. How does the production of sperm differ from the production of an ovum?
The production processes are very different. The formation of sperm is called spermatogenesis, which is a continuous process in males after puberty, producing millions of sperm every day. The formation of an ovum is called oogenesis. A female is born with all the potential egg cells she will ever have, and typically only one ovum matures and is released each month during the menstrual cycle.
5. Are there any similarities between a sperm and an ovum?
Yes, despite their many differences, they share two fundamental similarities. Both are gametes, or reproductive cells, created for sexual reproduction. Secondly, they are both haploid, each carrying 23 chromosomes in humans. Their primary purpose is to fuse during fertilisation to form a single diploid cell called a zygote, which contains a full set of 46 chromosomes.
6. Why is the ovum so much larger than the sperm cell?
The ovum’s large size is crucial for early life. It contains a rich supply of cytoplasm and stored nutrients. After fertilisation, this provides all the necessary energy and raw materials for the newly formed zygote to divide and grow during its journey to the uterus, before it implants in the uterine wall. The sperm’s only job is to deliver genetic material, so it is built to be small and fast.
7. What happens to the ovum if it is not fertilised by a sperm?
An unfertilised ovum has a very short lifespan, typically around 12 to 24 hours after it is released from the ovary (ovulation). If it isn't fertilised by a sperm in the fallopian tube within this timeframe, it begins to disintegrate and is eventually shed from the body along with the uterine lining during menstruation.
8. How does fertilisation occur when a sperm meets an ovum?
Fertilisation is the process where a single sperm fuses with an ovum, usually in the fallopian tube. The sperm uses enzymes in its head to get through the ovum's outer protective layers. Once one sperm successfully enters, the ovum's surface changes to block any other sperm. The genetic material from the sperm's nucleus then combines with the ovum's nucleus, creating a single diploid cell called a zygote.
