<span>In continental Middle America, climate and other
environmental conditions vary by altitudinal zone where Tierra fria rank 3rd
as the highest zone. Tierra nevada is the highest followed by Tierra helada,
Tierra fria, Tierra templada and Tierra caliente being the lowest.</span>
B. High regard as a way to enlarge the workforce
Answer:
In the deep ocean layers where the sunlight does not reach, these organisms that are chemoautotrophic use sulfides from the hydrothermal vents to perform chemosynthesis instead of photosynthesis.
Explanation:
Chemoautotrophic organisms are the ones that are adapted to the absence of sunlight. Such organisms identify electron donors in their vicinity and derive energy from the oxidation reactions that these electron donors (mostly, inorganic compounds) undergo.
The major reason for the development of such a trait in these organisms is the depth that they live at. On deep-sea floors, there is an abundance of sulfides. Thus, the organisms living on there make use of the sulfides to fix carbon and obtain energy the required energy to sustain.
The process of chemosynthesis occurring on deep-sea floors due to the presence of carbon, sulfides, and oxygen culminates in the production of organic materials as an end result which the organisms feed on and sustain even when there is no sunlight available. These organisms majorly belong to the bacteria species called Archaea and Extremophiles.
In this example, john's whistling is serving as a discriminative stimulus.
This procedure, studied by Ivan Pavlov, shows a stimulus ( in this case the action of John's whistling) and a response ( the cattle run to the food trough).
Pavlov studied it with dogs. He realised that when a trainer fed them, dogs salivated. So, he presented the dogs with a "stimulus" ( the sound of a metronome) and when he gave the dogs food. After a few repetitions, when the dog listened to the stimulus, it salivated.
