The correct answer is option A, that is, jaw or jawless fishes.
Agnatha refers to the superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, comprising of both the extinct (conodonts and ostracoderms) and present (cyclostomes) species. It comprises the group of all vertebrates with jaws, that is, gnathostomes.
On the other hand, there are two categories of living fish with jaws. The Osteichthyes (the bony fish) and the Chondrichthyes (the cartilaginous fish). Both the categories of fish comprises of two pairs of lateral fins and a finned tail for impulsion in water.
Skeletal muscle! (or striated muscle).
Atoms tend to form bonds because one atom may have more attraction to electrons than the other
Star is a brilliantly glowing sphere of hot gas whose energyis produced by an internalnuclear fusion process. Stars are contained in galaxies. A galaxy contains not only stars, but clouds of gas and dust. These clouds are callednebulae, and it is in a nebula where stars are born. In the nebula is hydrogen gas which is pulled together by gravityand starts to spin faster. Over millions of years, more hydrogen gas is pulled into the spinning cloud. The collisions which occur between the hydrogen atoms starts to heat the gas in the cloud. Once the temperature reaches 15,000,000 degrees Celsius, nuclear fusion takes place in the center, or core, of the cloud. The tremendous heat given off by the nuclear fusion process causes the gas to glow creating a protostar. This is the first step in the evolution of a star. The glowing protostar continues to accumulate mass. The amount of mass it can accumulate is determined by the amount ofmatter available in the nebula. Once its mass is stabilized, the star is known as a main sequence star. The new star will continue to glow for millions or even billions of years. As it glows, hydrogen is converted into helium in the core by nuclear fusion. The core starts to become unstable and it starts to contract. The outer shell of the star, which is still mostly hydrogen, starts to expand. As it expands, it cools and starts to glow red. The star has now reached the red giant phase. It is red because it is cooler than the protostar phase and it is a giant because the outer shell has expanded outward. All stars evolve the same way up to the red giant phase. The amount of mass a star has determines which of the following life cycle paths the star will take.
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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