Answer:
The correct answer is D. Desertification can happen as a result of non-sustainable agriculture.
Explanation:
Desertification is a process of ecological degradation in which the fertile and productive soil loses all or part of the production potential. This happens as a result of deforestation and destruction of the vegetation cover, the subsequent erosion of the soils, the overexploitation of aquifers, the over-irrigation and consequent salinization of the lands or the lack of water; human beings frequently favor and increase this process as a result of activities such as excessive cultivation and grazing or deforestation. According to data from the United Nations Environment Program (UNEP), 35% of the surface area of continents can be considered as desert areas, within these territories millions of people survive in conditions of persistent drought and food shortages. Among many other factors, it is considered that the expansion of these deserts is due to human actions.
Answer:
The Chemical Coupling:
A coupling reaction in organic chemistry is a general term for a variety of reactions where two fragments are joined together with the aid of a metal catalyst.
The Conformational Coupling:
The basic idea, as originally proposed by Robin Irvine, is that stimulation of the IP3 receptor (IP3R) by store emptying induces a conformation change that is transferred to the channel in the plasma membrane through a direct protein-protein interaction (3)
The Chemiosmotic Coupling
For approximately twenty years, it has been generally agreed, in accordance with the chemiosmotic theory, that the coupling of electron transfer reactions to ATP synthesis is mediated by a proton electrochemical gradient, often alternatively called a protonmotive force, generated across these membranes by electron
a. What is a star's spectrum?
A star's spectrum refers to the <em>"amount of light"</em> that stars they give off according to varying wavelengths. Since we cannot tell the amount of light a star gives off quantitatively from Earth, we can differentiate them according to how bright they appear.
b. Which spectrum is most common in stars?
Stars are classified according to their spectra <em>(elements in the star)</em>. They are classified into 7 types <em>(O, B, A, F, G, K and O). </em>The most common type is M, however, it gives off a dim light.
c. How can it differ from start to star?
Although stars follow a continuous spectrum, the spectra of a star differs from each other because <u>they do not give off the same amount of energy at the different wavelengths. </u>
d. What does the spectrum tell us about the star?
The spectrum can tell the<em> surface temperature</em> of the star. This means that a blue star (we often see it as a white-colored star from Earth) is hotter than that of a yellow star. A red star is considered the coolest star among all.
The spectrum of stars also allows the astronomers to study composition of the stars according to their <em>wavelengths.</em>