“Scientists have recently proposed a reorganization of the phylogenetic system of classification to include the domain, a taxonomic category higher than the kingdom category.”
A. The three-domain system allows for the conclusion that the previous five kingdoms were more connected than was believed. Out of the five previous kingdoms: Animalia, Plantae, Protista, Fungi, and Monera, four of the five kingdoms were placed in the same domain- Eukarya. The one remaining kingdom was separated into two domains- Bacteria and Archaea. This separation was unusual as it was previously thought that Bacteria and Archaea were closely related, as they were both prokaryotic.
It is now thought that Archaea is more closely related to Eukarya than it is to Bacteria. B. Recommendations to adopt this new three-domain taxonomic system were based on evidence more detailed and reliable than that of the five-kingdom system. New advances in genetic and molecular sciences have allowed for classification based on information such as base composition, nucleic acid hybridization, and amino acid sequences.
The two main molecular methods to identify microbes are by the comparison of 1) DNA and RNA sequences (nucleic acid hybridization) and 2) of amino acid sequences of a protein or proteins (amino acid sequences). Nucleic acid hybridization, a part of the field molecular genetics, is used to identify related DNA and RNA molecules. It takes into account single stranded genetic material’s ability to multiply into double-stranded genetic material, and how the double-stranded material (DNA) still has some resemblance to the one-stranded genetic material. DNA base composition is a genetic method used to compare related organisms through their genetic material (DNA).
This new more scientifically sound evidence has enabled new findings such as Achaea’s newfound relation to Eukaryotes. Physically, Archaea seemed to be more closely related to bacteria, but genetically Archaea has been found to have DNA that is structurally more similar to ours. It is believed that Eukaryotes were once a part of Archaea, but split off due to evolution at some point in history. C. The universal ancestor is the base organism from which all other organisms have evolved. The universal ancestor was most likely small, unicellular, prokaryotic, and contained a cell membrane. Its small size would have given it a low surface area to volume ratio and no internal transport system. The universal ancestor would have been completely self-contained and would have used its semipermeable cell wall for protection.
Remember! This is just a sample.
You can get a custom paper by one of our expert writers.
Get your custom essay
Helping students since 2015
Essay Writing Service Features
Our Experience
No matter how complex your assignment is, we can find the right professional for your specific task. Contact Essay is an essay writing company that hires only the smartest minds to help you with your projects. Our expertise allows us to provide students with high-quality academic writing, editing & proofreading services.
Free Features
Free revision policy
$10Free bibliography & reference
$8Free title page
$8Free formatting
$8How Our Essay Writing Service Works
First, you will need to complete an order form. It's not difficult but, in case there is anything you find not to be clear, you may always call us so that we can guide you through it. On the order form, you will need to include some basic information concerning your order: subject, topic, number of pages, etc. We also encourage our clients to upload any relevant information or sources that will help.
Complete the order form
Once we have all the information and instructions that we need, we select the most suitable writer for your assignment. While everything seems to be clear, the writer, who has complete knowledge of the subject, may need clarification from you. It is at that point that you would receive a call or email from us.
Writer’s assignment
As soon as the writer has finished, it will be delivered both to the website and to your email address so that you will not miss it. If your deadline is close at hand, we will place a call to you to make sure that you receive the paper on time.
Completing the order and download