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Answer:
Environments on Earth are always changing, and living systems evolve within them. For most of their history, human beings did the same. But in the last two centuries, humans have become the planet’s dominant species, changing and often degrading Earth’s environments and living systems, including human cultures, in unprecedented ways. Contemporary worldviews that have severed ancient connections between people and the environments that shaped us – plus our consumption and population growth – deepened this degradation. Understanding, measuring, and managing today’s human environmental impacts – the most important consequence of which is the impoverishment of living systems – is humanity’s greatest challenge for the 21st century.
Answer:
Action potentials from different sensory modalities are carried on different nerve tracts.
Explanation:
Action potential in the cells occur upon the stimulation of the signal. The action potential results in the change in the membrane potential of the cell and responsible for the transmission of nerve impulse.
Different sensory receptors are present on brain to sense the different action potentials of the body. The different sensory modalities are used for the different nerve tracts and information flows occur in the body in the specific area.
Thus, the correct option is (a).
Urine may also contain sulfate and phenol waste and excess sodium, potassium, and chloride ions. Thekidneys help maintain homeostasis by regulating the concentration and volume of body fluids. For example, the amount of H+ and HCO3 - secreted by the kidneys controls the body's pH.