Most scientists believe that for half of Earth's 4.6-billion-year history, the atmosphere<span>contained almost no </span>oxygen. Cyanobacteria or blue-green algae became the first microbes to produce oxygen<span> by photosynthesis, perhaps as long ago as 3.5 billion years ago and certainly by 2.7 billion years ago.
this answer came from this website </span>The Rise of Oxygen - Astrobiology Magazine<span>www.astrobio.net/news-exclusive/the-rise-of-oxygen/
it should help</span>
Out of all the options, only "Volcanic Eruption" is the rapid change
In short, Your Answer would be Option D
Hope this helps!
Answer:
The correct option is A
Countercurrent multiplication is the process whereby energy is used to generate an osmotic gradient in which water is reabsorbed from the tubular fluid to produced concentrated urine.
Explanation:
Countercurrent multiplication moves sodium chloride from tubular fluid into interstitial space deep within the kidneys. The concurrent multiplication process build up osmotic gradient interstitial fluid in a single effect. Here, sodium chloride is driven by active transport out of the tubular fluid in the thick ascending limb into the interstitial fluid, which becomes hyperosmotic. This result to water moving passively down its concentration gradient out of the tubular fluid in the descending limb into the interstitial space to a point where it attains a state of equilibrium.
Therefore,the correct option is A, where the ions leaves the ascending limb to make water comes out of descending limb.
Such changes would occur mostly likely near or in the active binding site of the enzyme.
Because the drugs used are competitive inhibitors of the <span>HIV reverse transcriptase enzyme, it means that they connect directly to the active binding site of this enzyme not allowing it to preform its function. If the mutations impede this drugs to work, it is probably because they alter the active binding site of the enzyme, not allowing the drug to bind and have its competitive behaviour permitting the enzyme to work normally. </span><span /><span>
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According to the cladogram, arthropods are MOST closely related to which group of organisms? mollusks. annelids. echinoderms.
