[Biology Class Notes] on Difference Between Sperm and Ovum Pdf

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.