Difference between Egg and Sperm cells
A gamete is a mature haploid (having half the number of chromosomes i.e., 23 chromosomes) male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a diploid (having the complete number of chromosomes i.e., 46 chromosomes) zygote, which results in Fertilisation.
Ovum is said to be the largest cell in the female body while, contrariwise, the smallest cell in the male body is the Sperm.
They also differ dramatically in shape .. male sperm are longer in size and consist of 3 regions .. head, midpiece and tail. The head region is covered, cap-like, with an acrosome which contains enzymes that help penetration of the outer membrane of the ovum, to permit the sperm cell to enter. The midpiece region stores the energy and the tail region helps in cell movement.
Female ova are larger and wider than male sperm and are round in shape, covered with a cell membrane which binds the sperm cells and helps in fertilization.
Sperm are produced in large numbers and have to be much smaller than the egg cell or ovum, as, in the female reproductive tract, to ensure the fertilisation of ovum, sperm cells “swim” up to meet the ovum. Hence, sperm are always smaller in size and more in number, to increase the chances of conception occurring by at least one of them entering the ovum. If a sperm cell was as big as an egg cell, it’s mobility would decrease. Nature has formed the sperm to contain only the necessary DNA and just enough energy stores to enable them to swim for a few days. They don’t have any mitochondria (whose purpose is to turn nutrients from the cell into energy) to carry out various functions. Sperm cells just use the stored energy they have and, if they have not fused with an ovum by the time the energy is depleted, they die.
On the other hand, the ovum is filled with both food and mitochondria in addition to its vital DNA. When it is fertilized, it draws on that food and becomes an embryo, on the way to becoming a fetus. Since the growing embryo does not get any nourishment from the mother until it is complete, the ovum requires enough food to sustain the embryo during the implantation process in the uterine wall.
For conception to take place, an egg cell and a sperm are required. After a while of the cells locating each other, they fuse and the chromosomes get together. Both the egg and sperm cells are produced by Meiosis, which is a special type of cell division, where the cells only have half the number of chromosomes, one from each pair. When the process of Meiosis is complete, 4 cells are formed = eggs or sperm. Each cell differs genetically from its parents. Fertilization of an egg by a sperm brings the chromosome count to 100%.
In the human body, there are no cells (like the Sperm and Egg cells) which are so different and yet cannot do without each other and belong together.