Answer: The group of participants who are exposed to the independent variable. These participants receive or are exposed to the treatment variable.
Explanation:
Bacteria in general grow optimally when the pH is around 7 (5-9 let's say). That is not to say that there are not bacteria that grow in extremely acidic conditions, like in our stomach, or others in extremely basic conditions, like the conditions near volcanoes. Nonetheless, bacteria that grow in food prefer acidic environments over basic ones and usually cannot tolerate the acidity of fruits which is around 4 pH for the most acid ones. For example, stuff like milk and bread that have a pH from 5-6 are prime examples of food where bacteria would thrive. Thus, the correct answer would be b.
The tigers have stripes because it is advantageous for them because they are an ambush predator and need good camouflage. The stripes are excellent camouflage for places that are shady, so the tiger can easily get close to its prey and attack it.
There's a very big possibility that the distant ancestors of the tigers did not had stripes. The reasons for that are different environment, but also that the stripes are actually a very rare type of pattern among the felidae family members.
As the environment started changing, the tigers needed to adapt to it, so they also needed a different camouflage. As some tigers in the population started to develop stripes, they were better hunters, thus were stronger, and seen as suitable mates for the females, as it would provide an offspring with the advantage that the male tiger has. Through this selection in the breeding process of mates that have advantageous camouflage patterns, the stripes were becoming more and more present, to the point where they totally pushed aside and eliminated the previously dominant camouflage pattern.
D. Decomposers return everything back to the environment
