Cells as the Most Basic and Fundamental Units of Life - Essay Example

The organic cells are of such a small size that they cannot be viewed without a scientific microscope. Their sizes range from 1 to 100 micrometers. Thanks to modern-day technology, detailed images of the most complex cells can be obtained through advanced microscopes. Mainly there are 2 types of cells, Eukaryotic and Prokaryotic; the first ones can be found in animals, plants, and fungi while the latter ones include bacteria and archaeans. Prokaryotes are single-celled organisms which were the most primitive forms of life on earth and are able to survive in the most extreme habitats.

Cell biology has made one of the most useful and interesting discoveries of modern times – DNA. DNA (deoxyribonucleic acid) is perhaps the key to finding the hidden truths about the human life cycle. DNA is a type of molecule known as nucleic acid and is located within the nucleus of cells (Bailey 2010). Chromosomes are the main component of reproduction; proteins and DNA are the main constituents within these chromosomes, therefore DNA serves as a major part of the reproduction cycle.

Cells have quite a complex structure, there are other structures contained in a single cell and are called Organelles. Each of these organelles carries out a specific task, just like the different organs of our bodies, which perform their specific function in order to enable the running of the over all system smoothly. Similarly, these organelles execute a wide range of functions within a cell that range from providing energy to reproducing hormones and enzymes. The Eukaryotic cells contain a different range of organelles and prokaryotic contain separate organelles, which are known as ribosomes. In the same way, plants and animals have different combinations of organelles but some of the elements are common throughout, such as Nucleus, Mitochondria, Endoplasmic reticulum, and Golgi complex.

The unique characteristic of cells is that different types of cells have different reproduction mechanisms for them. Fossils from primitive times came into their final form through a process called binary fission; most prokaryotic cells are produced by this process. Binary fission as the name suggests is a cloning process that results in two identical cells being derived from a single cell. While eukaryotic cells also have a similar mechanism called mitosis, it involves fusion reactions, in which cells combine together to form new organisms.

Eventually, most diseases are a result of cells not functioning properly. Cells self-destruct when they get infected or damaged, by a process called apoptosis. Apoptosis is just the opposite of mitosis; the inability of a cell to undergo proper apoptosis can result in the spread of cancer. Most of the cells in the human body have a very diverse life span. Their life can range from just a few days to a couple of years.