Q: What monitors the level of carbon dioxide in the blood? Read this paragraph and choose the correct option from the provided answers: The regular, rhythmic contractions of the diaphragm are controlled by the brain stem. It sends nerve impulses to the diaphragm through the autonomic nervous system. The brain stem monitors the level of carbon dioxide in the blood. If the level becomes too high, it "tells" the diaphragm to contract more often. Breathing speeds up, and the excess carbon dioxide is released into the air. The opposite events occur when the level of carbon dioxide in the blood becomes too low. In this way, breathing keeps blood pH within a narrow range. Choices: - the lungs - the heart - the kidneys - the brain stem A:
the brain stem

Q: How is the radioactive decay measured? Read this paragraph and choose the correct option from the provided answers: The rate of radioactive decay varies from one radioisotope to another. The rate is measured by the half-life. This is the length of time it takes for half of a given amount of a radioisotope to decay. Choices: - carbon dating - quarter-life - alpha emission - half-life A:
half-life

Q: Q: Which part of a fish helps them breathe? Read this paragraph and choose the correct option from the provided answers: Choices: - fins - layers - pores - gills A:
A: gills

Question: Q: The major component of a solution is called what? Read this paragraph and choose the correct option from the provided answers: The major component of a solution is called the solvent. The minor component of a solution is called the solute. By major and minor we mean whichever component has the greater presence by mass or by moles. Sometimes this becomes confusing, especially with substances with very different molar masses. However, here we will confine the discussion to solutions for which the major component and the minor component are obvious. Solutions exist for every possible phase of the solute and the solvent. Salt water, for example, is a solution of solid NaCl in liquid water; soda water is a solution of gaseous CO2 in liquid water, while air is a solution of a gaseous solute (O2) in a gaseous solvent (N2). In all cases, however, the overall phase of the solution is the same phase as the solvent. Choices: - solute - mixture - water - solvent A:
Answer: solvent

*Question*
Q: What is the organ in which gas exchanges take place between blood and air? Read this paragraph and choose the correct option from the provided answers: Respiration begins with ventilation. This is the process of moving air in and out of the lungs. The lungs are the organs in which gas exchange takes place between blood and air. Choices: - heart - skin - kidney - lungs A:
**Answer**
lungs

(Question)
Q: Which procedure helps modern nuclear physics convert lead into gold? Read this paragraph and choose the correct option from the provided answers: The alchemists were never successful in changing lead into gold. But modern nuclear physics can accomplish this task. Lead is subjected to nuclear bombardment in a particle accelerator. A small amount of gold can be obtained by this process. However, the cost of the procedure is far more than the amount of gold obtained. So the dream of the alchemists has never (and will never) come true. Choices: - nuclear fission - matter fusion - evaporation - nuclear bombardment A:
(Answer)
nuclear bombardment