The Concept Of The Prokaryote Valid And Useful Or Fundamentally Flawed?

You can identify a eukaryotic cell by its encased nucleus, containing the majority of its DNA and organelles surrounded by a membrane. Plant and Animal cells have double membranes and a housed nucleus therefore they are eukaryotic cells; organisms which do not contain a double membrane and an encased nucleus are known as prokaryotes, e.g. bacteria. The eukaryotic cell is made up of many membrane bound organelles which all have a specific function.

When life arose on Earth about 4 billion years ago, the first types of cells to evolve were prokaryotic cells. For approximately 2 billion years, prokaryotic-type cells were the only form of life on Earth. The oldest known sedimentary rocks found in Greenland are about 3.8 billion years old. The oldest known fossils are prokaryotic cells, 3.5 billion years in age, found in Western Australia and South Africa. The nature of these fossils, and the chemical composition of the rocks in which they are found, indicates that these first cells made use of simple chemical reactions to produce energy for their metabolism and growth. Eukaryotic cells evolved into being between 1.5 and 2 billion years ago. Eukaryotic cells appear to have arisen from prokaryotic cells, specifically out of the archaea. Indeed, there are many similarities in molecular biology of contemporary archaea and eukaryotes. However, the origin of the eukaryotic organelles, specifically chloroplasts and mitochondria, is explained by evolutionary associations between primitive nucleated cells and certain respiratory and photosynthetic bacteria, which led to the development of these organelles and the associated explosion of eukaryotic diversity. Today Prokaryotes

Currently, there are two major competing theories for the endosymbiotic origin of eukaryotic cells. The first theory claims that the eukaryotic cell is a combination of an archaeon with a

Prior to the development of DNA technology and the sequencing of organismal genomes, Charles Darwin suggested that the “tree” of life can be traced back to a single root (Koonin and Wolf, 2012). While Darwin’s theory was primitive, it laid the groundwork for the phylogenetic trees that are currently studied in science classrooms around the world. The three-domain tree, containing Eukarya, Archea, and Bacteria, soon became too simplistic due to the realization that some bacteria possessed the ability to exchange genetic information by horizontal gene transfer (Koonin and Wolf, 2012).

Prokaryotic cells do not have a nucleus. The chromosomes which are found in prokaryotes are usually spread in the cytoplasm. In eukaryotic cells the chromosomes remain together inside the nucleus and there is a clear nuclear membrane that is surrounding the nucleus.

Well prokaryote is the name given to organisms that are made up from cells that lack a cell nucleus or cells that lack any membrane-encased organelles (a specialized subunit within a cell). In lamens terms, in prokaryotes, the DNA is not bound or held together inside a nucleus. Prokaryotes also only have a single loop DNA. Last but not least prokaryotes are divided into groups or domains but more about that in a minute.

The purpose of this study is to identify four unknown organisms. The unknown organisms have been assigned randomly to six-research groups by Professor Hoffman. Each research group was provided two eukaryotes and two prokaryotes. The unknown organisms will fall into the following classifications: bacteria, algae, fungi, or protozoans. All living organisms are organized into one of three domains of life, Bacteria, Archaea, and Eukarya.

1. The feature that most clearly separates eukaryotes from prokaryotes is the presence of _______ in eukaryotic cells.

On the planet, Earth, prokaryotic and eukaryotic are the two major types of cells. Prokaryotic cells are defined as cells with genetic material and cell chemicals all enclosed within a cell wall, and having no defined organelles or nucleus (except ribosomes). Organisms in this group are small in size and mainly consist of bacteria. Eukaryotic cells, however, are defined as having a ‘’true’’ nucleus, membrane-bound organelles, and chromosomes. The nucleus of eukaryotic cells houses the deoxyribonucleic acid (DNA) and directs the synthesis of proteins and ribosomes. Prokaryotic cells, however, are much older cells as these cells are quite ancient and were the only form on planet Earth for billions of years, soon giving birth to eukaryotic cells 1.5 billion years ago.

One major difference (and one often used to distinguish the two) is the lack of a

Since the genetic resemblance of Prokaryotes is much lower than Eukaryotes and the gene isolation of Prokaryotes may take longer time to complete, the number of Prokaryotes we predicted

Some the evidence for this theory include the mitochondria and plastids which can be identified in a eukaryot; however, prokaryotes originally also have the same functional capabilities as the mitochondria, as well as plastids. Perhaps the mitochondria’s development is simply a result of condensing the process of energy creation into a single organelle and the development of plastids was a result of prokaryotes also being capable of completing a similar task; however, felt the need for condensing this task into a single

In this essay, I will discus protists as the first eukaryotic organisms, the parameters used to classify protists, including feeding, reproduction and their unique features. The kingdom Protista is an artificial grouping, defined only by what members of this group are not: protists are neither plants nor animals nor fungi, nor are they bacteria or archaeans (Cain, 2012, p. 55). Biologists today, still agree that protista is an artificial kingdom, composed of groups with very different evolutionary histories. Several classifications have been developed, split, and assigned to different members, such as, Plantae, Fungi, and Animalia. Protista is a category of eukaryotic organisms that have not been formally assigned to other kingdoms or to separate kingdoms of their own (Cain, 2012, p. 55).

The Serial Endosymbiotic Theory (SET) was a hypothesized process by which prokaryotes give rise to the first eukaryotic (an organism which contains a nucleus and organelles enclosed within a membrane ). Was pioneered in the 1960’s by the seminal work of Lynn Margulis. This theory attempts to explain the origins of eukaryotic cell organelles, specifically the mitochondria (providing the cells ATP (used for the cells metabolism) supply used by the cell as chemical energy ). With the theory suggesting that the mitochondria and plastids within a eukaryotic cell were once independent prokaryotic cells (a single celled organism, which contains a nucleus and other organelles that are absent of a membrane ), having been obtained by another organism through endosymbiosis, to become endosymbiot around 1.5 billion years ago. Where the eukaryotes several key organelles originated through a process called symbiosis, with this occurring between separate single celled organisms (prokaryotic cells). Through research and locating molecular and biochemical evidence, it suggests that the mitochondrion developed from proteobacteria, and chloroplast from cyanobacteria.

Eukaryotes come in two grades of organization: single-celled (protists) and multicellular (plants, animals, and fungi). The world today is full of complex multicellular plants and animals: how, why, and when did they evolve from protists?