The answer is C because if a doctor only tested new medication on one person then gave it to many other people with the same disease there might have been a mistake and could kill people
<span>The burners must be turned off because, in the case of liquid chromatography, the eluant solvents being used are flammable. Leaving the burners lit could cause the eluant to catch on fire, putting the scientist at risk.</span>
Answer:
(A) -> (D) -> (C) -> (B)
Explanation:
First off, given that the problem requires us to explain how life on Earth may have arisen <u>from terrestrial origins</u>, we can discard sentence (E), as impacts from meteorites would count as extraterrestrial origins.
Then it's just a matter of describing the steps by which simple compounds turned into more and more complex structures, that would in turn lead to the origin of life.
Simple inorganic compounds (such as CO₂, or NH₃) were exposed to energy, because of that they formed simple organic molecules, like carbohydrates or amino acids.
These organic molecules, in turn, would self-assemble into more complex structures, such as proteins.
Lastly, there's the phenomenon of Compartmentalization, where large organic structures became enclosed within a membrane-like structure, separating them from the 'outside' medium and thus creating primitive cells.
Answer:
1.
Explanation:
Xylem cell is a plant vascular tissue that conveys water and dissolved minerals from the roots to the rest of the plant and also provides physical support. Xylem tissue consists of a variety of specialized, water-conducting cells known as tracheary elements.
2. Phloem is the vascular tissue in charge of the transport and distribution of organic nutrients. The phloem is also a pathway to signaling molecules and has a structural function in the plant body.
3. Stomata are composed of a pair of specialized epidermal cells referred to as guard cells. Stomata regulate gas exchange between the plant and environment and control water loss by changing the size of the stomatal pore.
4. Guard cells optimize leaf gas exchange in response to changing environmental conditions and their turgor is controlled by alterations in atmospheric CO2 concentration, light intensity, humidity, and the drought hormone abscisic acid.