Answer:
<em>a. What is the significance of the rainfall? </em>These bacteria resist desiccation, and its dispersion is favored by winds. A decrease in rainfall means a dryer environment, which the bacteria can resist and makes it easier for the cell to be carried somewhere else by winds.
<em>b. The etiologic agent of the disease is </em><em>Coxiella burnetii</em>
<em>c. This is an example of</em> a zoonosis
Explanation:
Q fiber Pneumonia is a zoonosis world-widely distributed and of global importance, which etiologic agent is <em>Coxiella bunetti</em><em>.</em>
- Zoonosis: Referred to as the infectious diseases that are naturally transmitted from animals to human beings. Among zoonotic pathogens, there are bacteria, viruses, or parasites. They propagate by direct contact, water, and wind, among others. These diseases represent a global importance problem due to the close ties with animals. Zoonotic diseases increase even more as human being keeps dispersing and invading natural wild environments to raise cattle and farm, among other activities.
- The etiologic agent is the element that propitiates the origin and evolution of a disease. Many bacteria and viruses might be considered to be one of the most common etiological agents.
Populations in contact with goats, sheep, and cattle, use to have a positive result for antibodies against <em>Coxiella burnetii</em>. This bacteria is transmitted to humans orally and by inhalation. The microorganisms resist extreme conditions and are highly infectious. The inhalation of only one cell can produce an important infection in the host. It resists desiccation and any other environmental degradation. They can persist for several months and be transported by winds to farther places. This makes it even more difficult to determine the epidemiologic origin.
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Answer:
Bacteriophages (phages) are viruses that infect only bacteria and do not infect mammalian or plant cells. Phages are ubiquitous in the environment. Phages or bacteriophages were chosen as a model system for their simplicity, as they only contained protein-coated nucleic acid. Alfred D. Hershey and Martha Chase (who were part of the bacteriophage group) in 1952 studying the infection of the bacterium Escherichia coli by the T2 phage show that the information definitely resides in the DNA. They used phage with either [32P] -labeled DNA or [35S] -labeled proteins to infect the bacteria. Immediately afterwards, they centrifuged the sample so that the infected bacteria remain in the pellet and the virus capsids (proteins) remain in the supernatant. [35S] is found in the supernatant, whereas [32P] is found in bacteria. After one cycle of infection, it was observed that when phage labeled in the [35S] proteins were used, only 1% of the radioactivity was incorporated into the progeny. But when phages were [32P] labeled, more than 30% of the radioactivity was in the progeny. They showed directly that what is transmitted from one progeny to another is the DNA and not the proteins, despite having first "diluted" in a bacterium.
Explanation:
Bacteriophages are viruses that infect bacteria in a specific way. Bacteriophages, like other known viruses, are found in an intermediate zone between living organisms and inert matter. Bacteriophages bind to the host pathogenic bacterium, introduce their genetic material, replicate inside it and destroy it. Hersey, along with his assistant Martha Chase, used phages because they knew that T2 phages were made up of 50% proteins and 50% nucleic acids and that phages entered bacteria and reproduced. As the progeny carried the same infection traits, the genetic material of this had to be transmitted to the offspring, but the mechanism was unknown. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the bacterium Escherichia coli, which it reproduces by attaching itself to the outer wall of the bacterium, injecting its DNA into it where it replicates and directs the synthesis of the phage's own proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or disrupt the cell and release phage from progeny. They infected a culture of bacteria with radioactively labeled phages: the protein coat with sulfur (35S) and its DNA with phosphorus (32P). After infection, they separated the phages from the bacteria by violent shaking using a mixer (hence the name of the experiment). By centrifugation the much smaller phages remained in the supernatant and the much larger bacteria in the pellet. 85% of the radioactivity corresponding to DNA appeared in the pellet and 82% of the protein in the supernatant. This result supported the idea that DNA was the only component of the bacteriophage that penetrated the interior of the bacteria and, having the ability to form new phages, constituted the genetic material.
Answer:
D
Explanation:
Because every system in the body is vital
An organism that cannot make its own food is called a heterotroph. All animals and species of fungi, along with some types of bacteria, are heterotrophs.
Answer:
Thyroid hormones
Explanation:
Animals and people exposed to pesticides such as insecticides, fungicides, and herbicides, have shown to be affected by their effect on the thyroid. These chemicals can produce endocrine alterations acting as thyroid disrupters. They affect many mechanisms in the organisms such as inhibition of thyroid iodine uptake, <u><em>interference with the thyroid hormone receptor</em></u>, binding to transport proteins, among others. They cause toxicity in the functioning of the hypothalamic-pituitary-thyroid axis.
There are many studies that associate thyroid diseases with exposure to organochloride pesticides. Significant alteration in the TSH, T3, and T4 levels have been expressed by people directly or indirectly exposed to the chemicals.
