Genetics 5

Genetics
1. Bacteria grow rapidly and have a short life and therefore do not have the luxury to manufacture complex proteins that they may not need. Complex organisms do have non-coding gene sequences mixed with coding ones because of the need to mix and match them to make new proteins that may be useful to the organism.
2. The evolution of eukaryotes happened from the most basic and universal functions towards the most secondary ones. The mitochondrion is more basic than chloroplast since all cells need energy and therefore it was taken in earlier than the chloroplast. As evolution continued, the photosynthetic prokaryote was taken in by the plant cell to solve the need for carbon fixation. According to taxonomical classes,mosses and pine trees both belong to the kingdom Plantae and thus may be closer as compared to mushrooms that belong to the kingdom Fungi. By evolution, since mosses contain chloroplast just like pine trees, it can be concluded that they are closer to pine trees than they are to mushrooms since they have gone one evolutionary step further together.
3. The ratio of human cells to bacterial cells in the human body is roughly 1:10 and these bacteria do play a role in and on the human body. An important role they play would be providing an invisible protective armor that keeps foreign insults at bay. This protective barrier exists on the human skin or the digestive system as normal and essential flora whose disturbance leads to severe infection by infectious microbes.

4. For bacteria to launch a formidable attack on an enormous host, they not only need numbers, but well-synchronized group action. In order to achieve this communication is necessary. Individual action by a single bacterium cannot achieve virulence. This communication is relevant to us because it helps us understand how virulence happens during a bacterial infection.
5. Bacterial virulence is in many forms like toxins, cell surface proteins and carbohydrates that aid the bacteria in causing damage to its host. Virulence plasmids assist in passing on the genes that code for these properties to other bacteria. If these virulent plasmid happen to be conjugative, meaning they can facilitate their own transfer, then it is a cause for alarm. This is because the virulence genes cannot be lost since their transfer is assured throughout generations.
6. Vocabulary
a. Mitochondria: Cell organelles that generate energy in the form of Adenosine Triphosphate to power cellular metabolism. Their inner membrane is highly coiled to provide maximum surface area for this function. They are indispensable in multicellular complex organisms.
b. Endosymbiosis: A phenomenon whereby one organism lives in another, and both are beneficial to each other, even though sometimes it the relationship can be pathogenic.
c. Bacteria: Tiny single-celled organisms that existed before all other organisms. They are classified as prokaryotes since they lack a nucleus and other organelles.
d. Archaea: A domain of life alongside eukaryotes and bacteria consisting of single-celled organisms like bacteria but different from bacteria because of some molecular differences. These differences include the lack of peptidoglycan in their cell wall while bacteria do have it and having unmodified methionine in their initiator tRNA whereas bacteria have modified methionine.
e. Quorum Sensing: The ability of a bacterium to measure the concentration of chemical signaling molecules secreted by other bacteria so as to enable a certain coordinated group behavior. This concentration reflects the number of bacteria in the environment for the group action to be successful. It is very useful in launching virulent activities like secreting toxins.
f. Receptor: On the surface of any cell there are protein molecules that serve as a means for communication to affect cellular activity once they interact with other chemical mediators. Chemical signaling happens when a chemical molecule binds to the receptor which in turn transmits a certain message to the cell making the cell respond in a particular way.
g. Virulence: The ability of bacteria to be pathogenically harmful to its host by having properties like toxins, cell surface proteins and carbohydrates that attack the host as well as those that protect the bacteria from being destroyed by the host like bacterial capsules.
h. Inter-species communication: In bacterial communities, communication is essential between bacteria of different species and this happens through a generic molecule that is produced by all bacteria. Thus bacteria are multi-lingual. This communication helps the bacteria to detect the presence of other species and also estimate their population ratios.
i. Conjugation: This is the transfer of bacterial plasmids from one bacterium to another, and it normally involves either contact or the sex pili, and both bacteria remain with a copy of the plasmid. It can happen within the same species or across species and is the cause of bacterial evolution.
j. Compatibility: Is when two different plasmids live in the same cell while maintaining stability. It is common when the plasmids are not closely related and they belong to different compatibility groups of the known 30 because the partition systems do not compete. Competition between plasmids eliminates the weaker plasmid.

References
“How bacteria “talk” – Bonnie Bassler.” Youtube.com, TED-Ed, 9 Feb.2013, https://www.youtube.com/watch?v=KXWurAmtf78&t=820s
“Radiolab.” Cellmates. N.p., 2016. Web. 13 Jan. 2018.