Answer:
Naloxone is an antagonist at opioid receptors and heroin is an agonist at opioid receptors
Explanation:
An agonist is a substance that binds to a receptor and causes a biological reaction. In this case, heroine binds to opioid receptors. An antagonist blocks the reaction from the agonist, impeding the receptor's activation. Agonists and antagonists work for specific receptors, and for an antagonist to block an agonist they must bind to the same receptor, like naloxone does with heroin. Giving an antagonist that binds to one receptor and and agonist that binds to a different one means that the antagonist will have no effect.
Xylem and phloem fiber cells
The correct answer is D. Salt water.
Explanation
The hydrosphere is the system that groups all the waters of the earth that include oceans, seas, rivers, lakes, lagoons, frozen waters like ice and snow, among others. The water of the earth can be classified between salt water and freshwater, within the first group we find the oceans and the seas that represent two thirds of the total water of the earth, that is, 93 percent of the total water of the earth, a figure close to 1 370 323 000km³; the rest of the water is fresh and consists of rivers, lakes, lagoons, streams, groundwater, and glaciers. So, the correct answer is D. Salt water
