Answer:
1- Option A) describes an index fossil. Trilobite existed for a short time, but was abundant and lived in many locations.
2- Option B) Continents were once joined and have since drifted apart.
Explanation:
1) Fossils are animal and vegetable rests found in different strata of sedimentary rocks. Sedimentary layers deposit chronologically, so they are used to reflect history. They keep in each layer some of the forms of life that inhabited that area in the past. These fossils turn to be very useful while dating ages. The term Index fossils refer to those fossils that only existed in a given era or geological period during evolution.
Index fossils must:
• Be easily recognizable and distinguishable from all the other fossils
• Have lived in a relatively short geological period
• Present a wide geographic distribution
• Have lived in different sedimentary basins
• Appear in different types of rocks
• Be abundant
<em>A) Trilobite existed for a short time, but was abundant and lived in many locations. </em>The species accomplish the requirements. It is easily recognizable, had a wide geographic distribution, was abundant, and lived for a short time.
2) The tectonic plates theory states that there is a continual movement of the crust. It explains the movement of the different plates and their directions and interactions. The continental drift theory explains how these movements have been taking place since millions of years ago. When continents were together in a unique continent, many species used to inhabit it. When plates started to separate, they took some of these species that got apart by the ocean. Some species were already dead and fossilized, while some other organisms died during continental drift and got fossilized after the divergence. <em>The existence of the same fossils, placed in the same layers and of the same age, suggests that they used to inhabit the same area and died during the same time, meaning that continents were together when they got fossilized. </em>
Answer:
The answer of the human body to stress, and stressful situations, including to conditions that may trigger the stress response of the body, is a pretty complex one involving the nervous system as a whole, and the adrenal glands, which are responsible for producing two of the most important stress-related hormones. These hormones: glucocorticoids and corticoids (cortisol), will in turn affect all body systems in different manners to produce the necessary effects, to respond to the perceived "threat".
In essence, we have a pathway from our brains, to our adrenal glands, known as the hypothalamic-pituitary-adrenal (HPA) axis. In this axis, several genes that are geared towards stress responses activate (CRHR1 and CRHR2, among others) and produce CRH (Corticotropic releasing hormone), which in turn is directly related with stimulating the production of cortisol when there is stress. However, because our bodies are not meant to be in a constant state of alertness and preparation, because the different organs of the body are negatively affected, there are also pathways that will turn off this response and lower the stressful production of cortisol.
In this particular person, although he has been exposed to the same stressor as the others, he does not have precisely the same reactions to it as the others. It is important to note one thing here, and that is, that the stressor offered to these people were videos of stressful situations, and what is known about the stress response is that one vital part of it is visual exposure to different factors, including light, and images. These exposures cause the HPA axis to initiate a response through CRH production. However, it seems that in this young man, although most of the responses are present, not all of them are. So one solution could be that he has a mutation in his genes in his HPA axis, and therefore CRH is not being produced in enought levels to stimulate sufficient levels of cortisol production. However, there are also other genetical reasons why, and these could be many.
The statement above is TRUE. Inspecting food deliveries and storing them away immediately is part of the receiving process, which must be dully observed at all time in order to prevent food contamination, which can have a lot of undesirable serious effects on the consumers.
Answer:
no not actually
Explanation: the notheren lights are caused by earths magnetic field what youre thinking of when a star explodes it creates a supernova.
