Theory of Symbiosis

 

Explanation of theory

The theory of symbiosis is a theory of evolution that seeks to show how the prokaryotic organisms developed from eukaryotic cells. It proposes that this development took place following the symbiosis of the organelles that distinguished the eukaryote cells (Martin, Garg & Zimorski, 2015). This theory further states that mitochondria, plastids, and other organelles that seem to have undergone endosymbiosis while they were essentially prokaryotes that essentially were free-living. A result of this situation is that mitochondria seem to be related to Rickettsialles proteobacteria, and plastids such as chloroplasts seem to be related to nitrogen-fixing filamentous cyanobacteria. One of the biggest supporting evidences concerning the theory of symbiosis is that new mitochondria tend to form only through binary fission, and this is especially considering that cells cannot create new plastids. Moreover, the theory suggests that porins, which are essentially transport proteins, can be found in the outer membranes of bacterial cell membranes, mitochondria, and chloroplasts; showing a common origin of these organisms. Finally, evidence shows that some mitochondria and plastids have certain DNA molecules that are extremely similar to the DNA contained in bacteria; further advancing the theory of symbiosis (Morelli & Rosano, 2016).

Weaknesses

One of the most significant weaknesses of this theory is the claim stating that circular mitochondria DNA is similar to the binary fusion found in bacteria. An important difference is that the most pertinent components tend to be more eukaryotic in form than prokaryotic, which is in addition to the fact that replication is different between mitochondrial DNA and bacterial DNA. Moreover, despite their being enclosed in a double membrane, the structures of bacteria and mitochondria are essentially different and this is to such an extent that when antibiotics are administered, they end up in a situation where they are better able to distinguish between the mitochondrial and bacterial membranes (Harish & Kurland, 2017). This is an important factor because it shows that membranes are structurally different, meaning that the theory of symbiosis is disproved. One of the biggest arguments made by proponents of the symbiotic theory is that mitochondria and bacteria share similar characteristics, especially when it comes to size and shape. However, findings show that mitochondria have more of a bacillus shape and are not spherical as initially assumed.

Strengths

The biggest strength of the theory of symbiosis is that it advances the theory of evolution. This is especially considering that it advances the theory, proposed by Charles Darwin, of natural selection. The symbiotic relationship between cells and organisms seems to have played a role in the evolution of diverse organisms because many of them ended up coming together to advance certain characteristics. The theory of symbiosis also shows that organisms, which developed as a result of the symbiotic relationship, ended up in a situation where they not only grew apart, but in some instances came together in order to ensure their own survival (Booth, 2014). Only the strongest were able to make sure that they passed on their DNA to future generations, while at the same time advancing a situation where they either out-competed other species, or were able to avoid extinction.

The Orchid Cattleya Flower

 

Orchids are known to have been popular since the ancient Greek period, and this popularity continued way into the Middle Ages. This is especially considering that during the Middle Ages, orchids had acquired a number of uses, because of the belief that they had healing powers. In addition, orchids were believed to symbolize love, beauty, and luxury, with the last quality essentially being based on the rich most often being in possession of this flower. In this paper, there will be an analysis of the Orchid Cattleya, especially its division and classification.

The Orchid Cattleya was originally brought from Brazil, and one of the first owners of these flowers was a William Cattley, who had established an exotic orchid collection. Following the flowering of his collection, he sent a sample to an orchidologist, for analysis because it had yet to be classified (McMillan, Palmater and Cating 426). The result was that the flower was described as essentially a new genus, which was named Cattleya in honor of Cattley. The naming of this new genus can be considered an important event because it opened the way for the continued classification of the various species of this type of orchid.

The Orchid Cattleya comprises of more than forty species that can be found all over the world. In addition, because of its considerable popularity, steps have been undertaken to ensure that hybrids that capture its most attractive aspects are developed (Leal et al. 622). A result has been that since the early 1800s, these orchids have been found in the private collections of various people, and when they became more popular, there they have become prominent among people all over the world. Therefore, rather than being found only in its native Central and South America, the various species of Orchid Cattleya have become common in almost all continents.

One of the most important aspects of the Cattleya flower is that it consists of three narrow petals and a corresponding number of larger petals. Moreover, the number of flowers that a Cattleya can produce varies, and this can range between one and ten flowers. Despite coming in a wide diversity of colors, these flowers cannot be found in pure black or blue colors (McMillan, Palmater and Cating 426). The Cattleya consists of two categories, the first being those that have a single leaf, or monofoliates, and the second with two or more leaves, or bifoliates.

In conclusion, the popularity of the Orchid Cattleya has developed in such a way that it has become one of the most prominent flowers in the world. This is a trend that begun in the 18^th century when orchid gardens became extremely popular, especially in Europe. However, very few botanists seem to have studied them despite their being associated with the wealthy. The efforts of William Cattley ensured that this type of orchid was found to be a completely new genus, and it resulted in a situation where it not only received his name, but it opened the doors for the further study of the various species within it.